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LABORATORY GUIDE BOOK BASIC&ORGANIC CHEMISTRY BASIC CHEMICAL PROCESS LABORATORY DEPARTMENT OF CHEMICAL ENGINEERING FACULTY OF ENGINEERING UNIVERSITY OF INDONESIA DEPOK 2015

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  • LABORATORY GUIDE BOOK BASIC&ORGANIC CHEMISTRY

    BASIC CHEMICAL PROCESS LABORATORY

    DEPARTMENT OF CHEMICAL ENGINEERING

    FACULTY OF ENGINEERING

    UNIVERSITY OF INDONESIA

    DEPOK 2015

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    2

    VISION AND MISSION DEPARTMENT OF CHEMICAL ENGINEERING

    VISION

    To become a world class Chemical Engineering Department as center of

    excellence for education and research in chemical engineering

    MISSION

    The Department seeks to provide the best quality of undergraduate and

    postgraduate education. The Department will provide a broad-based education

    and design experience, enabling students to address chemical engineering

    problems. Furthermore, the Department will provide students with fundamental

    elements to develop in the profession in response to rapidly chaning technology

    and societal needs and expectations, and, will also develop important soft skills

    such as problem solving, communication, and group skills.

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    3

    BASIC & ORGANIC CHEMISTRY LABORATORY

    EXPERIMENTS:

    1. Physical and Chemical Properties

    2. Separation and Purification of Substances

    3. Reactions of Acids and Bases

    4. The Reaction of Metals with Acids

    5. Water Crystals

    6. Identification of Hydrocarbon

    7. Identification of Alcohol

    8. Lipid, Oil, Soap, and Detergent

    9. Extraction and Identification of Fatty Acids from Corn Oil

    10. Properties of Carboxylic Acids and Esters

    11. Carbohydrates

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    4

    Laboratory Regulation

    1. All practitioners must wear white lab jacket during the lab work.

    2. All practitioners must be present 10 minutes before the pre-test begins and sign the

    presence list.

    3. All practitioners must handle Introduction Report and Lab Journal to the assistant

    before the lab begins. All journals can be requested again to the assistant after joining

    the pre-test.

    4. All practitioners must participate the pre-test before the experiment is done until the

    responsible assistant have appraised that he is proper and able to do the given

    experiment module. If the practitioners do not join the pre-test, the experiment is

    stated as null and void. The pre-test is taken place for 10 to 20 minutes.

    5. All practitioners must make a note of all observation results from the experiment that

    should be done in the Lab Journal. In the end of the experiment, all the observation

    results must be known and signed by the assistant.

    6. The lab work report must be completed in a week after the lab work to the assistant.

    Delayed report will be given punishment and they will not to be allowed to join the

    lab work at transfer of the lab work report.

    7. The lab work report that has not fulfilled the requirements must be fixed and handled

    to the assistant in a week after it has been stated as a need to be fixed.

    8. Borrowing the devices of the lab work must be permitted by the laboratorys

    employee and returned them in the same condition.

    9. Before leaving the laboratory, practitioners must clean the desk and the equipment;

    also put in order the material and the equipment.

    10. The use of the equipment and chemical material must be careful, do not spill it.

    11. Damage of the castaway equipment/material that happens because of working error

    and practitioners negligence must be substituted by the practitioner with the same

    equipment/material.

    12. Be well mannered to the laboratorys employee and the assistant.

    13. The absence of practitioners on the scheduled date will get punishment, and will be

    considered as null and void, except there is an acceptable reason e.g. unavoidable

    calamity.

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    5

    14. The absence caused by sickness, the experiment can be done with the assistants

    agreement beyond the lab works schedule, after having the permission from the Lab

    works University coordinator. The dispensation of rescheduling that is caused by

    sickness only permitted once during the lab works period.

    15. The requirements to pass the lab subject:

    Have participated in a pre-test and handled the Introduction Report and Journal

    before the lab works begun.

    Have performed all experiments in the same semester and stated as Pass by the

    assistant.

    Handle the lab works report for all of the experiments that have been done and

    scored by the assistant.

    Pass the final test of the lab work.

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    6

    Laboratory Report Format

    I. PRE-REPORT AND JOURNALWRITING

    DATE

    EXPERIMENT 1

    TITLE

    I. OBJECTIVE II. LAB WORK PRINCIPLE III. EQUIPMENT AND CHEMICALS IV. PROCEDURE AND OBSERVATION

    EXPERIMENT LAB WORK PROCEDURE OBSERVATION RESULT

    A

    1.

    2.

    3.

    4.

    B

    1.

    2.

    3.

    4.

    Laboratories :

    Name/NPM : 1. . 2. .

    Signature of Laboratory Assistant

    ( )

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    7

    II. LAB REPORTWRITING

    II.1. COVER

    ORGANIC CHEMISTRY LAB REPORT

    EVEN/ODD SEMESTER 201/201

    GROUP

    NAME : 1.

    2.

    NPM : 1.

    2.

    BASIC CHEMICAL PROCESS LABORATORY

    DEPARTMENT OF CHEMICAL ENGINEERING

    FACULTY OF ENGINEERING

    UNIVERSITAS INDONESIA

    DEPOK 201

    II.2. CONTENT

    DATE

    EXPERIMENT 1

    TITLE

    I. THEORY

    II. DATA PROCESSING

    III. OBSERVATION RESULT ANALYSIS

    IV. ASSIGNMENT AND QUESTION ANSWER

    V. REFERENCE

    GROUP :

    1. .NPM .

    2. .NPM . Signature of Laboratory Assistant

    ( )

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    Common Procedures and Concept

    To get an accurate result during the experiment, it is important to know the basic

    principle related with laboratory equipment utilization.

    I. Heating

    Most of heating process in laboratory are done with gas burner. For some cases, we

    will use oven equipment during this process. Bunsen burner (from the figure below) usually

    has 2 valves for gas and air arrangement.

    To turn on a bunsen burner, please follow these steps:

    Air valve is in a closed condition,while the gas valve is in an opened condition

    Turn it on with matches. From this step, we will see a not-too-hot red flame

    To get a better flame and higher temperature from the bunsen burner, open the air valve

    slowly until the blue flame appear.

    After combustion, turn off the bunsen burner by closing the gas flow.

    If the bunsen burner is used for heating a substance in a beaker glass / test-tube , the

    steps can be seen from this figure below:

    Attention! Dont aim the mouth tube to another peoples face!

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    II. Filtration

    Filtration aims to separate a liquid substrate from the solids one by passing the

    substrate through a filter paper. The filtration procedure is as follows:

    Fold the filter paper like the figure below:

    Set it on the funnel, then wet the filter paper with distilled water and avoid any air cavity

    behind the filter paper.

    Note that the position of the filter paper must 0.5-1 cm from the top edge of

    the funnel and the amount of sediment is 2/3 from the maximum height of the

    filter paper.

    Heating or burning process for

    components inside the reaction tube.

    Heating process of Baker glass using

    Bunsen burner.

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    Set the funnel in the buffer reservoir dan put the vessel under it.

    Pour the liquid substrate through a stirring rod carefully.

    Rinse several times with distilled water until completely clean

    III. Scale Reading

    In a fluid-volume measuring equipment, contained circular lines mark which

    indicating the height of limit on the volume of fluid given. As the boundary surface reading is

    part of curved liquid, except for liquid whose color is dark, read at the top of the curved

    surface of the liquid. More details can be seen in the figure below:

    IV. Washing Equipment

    All of the equipements used in chemical laboratory must in a clean condition. The

    clean equipment can be known when if the surface wetted, there will be a new layer of

    distributed liquid. The prescense of fat or dust will cause uneven coating distribution.

    Washing/cleaning equipment is done by washing it with detergen , scrubbed it with a

    brush if necessary, then rinse it with distillate water. To wash the equipment which is very dirty,

    it is important to use potassium dichromate solution in sulfuric acid. How to make the solution

    can be asked to the assistant.

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    Experiment 1 PHYSICAL AND CHEMICAL

    PROPERTIES

    I. OBJECTIVES

    Distinguishing physical and chemical properties of a substance.

    II. INTRODUCTION

    Aaaaaaaaaa

    III. EQUIPMENT & CHEMICALS

    III.1. Equipment

    1. Bunsen

    2. Test tube clamp

    3. Rubber suction

    4. Measuring cylinder 10 ml

    5. Ni-Cr wire

    6. Test tube

    7. Graduated/Measuring pipette

    8. Funnel

    9. Beaker glass 100 ml

    10. Washing bottle & Pipette

    III.2. Chemicals

    1. Zinc (Zn)

    2. Copper (Cu)

    3. Magnesium (Mg)

    4. Iron (Fe)

    5. Aluminum(Al)

    6. Calcium carbonate (CaCO3)

    7. Cupric nitrate (Cu(N03)2)

    8. Calcium hydroxide (KOH)

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    9. Concentrated sulfuric acid (concentrated H2SO4)

    10. Sodium hydroxide solution (NaOH solution)

    11. Acetic acid (CH3COOH)

    12. Calcium hydroxide (Ca(OH)2)

    13. Hydrochloric acid (HCl)

    14. Salt/sugar

    15. Methanol/benzene/toluene/ether

    16. Wood

    17. Calcium carbonate/CaCO3

    18. Distillated watert

    IV. PROCEDURES

    IV.1. Physical Properties

    1. Observe and record the shape, color, and smell of the following substances: Methanol,

    CaCO3, sugar, Toluene, Benzene, HCl and NaOH.

    2. Dissolve each substance in the water. Shake the solution, observe and record the

    changes.

    3. Do the step number 2 to ether.

    4. Explain how to identify substances that have the same shape and color, based on

    the physical properties of these substances.

    IV.2. Chemical Properties

    A. Changes caused by base effect

    1. Insert a piece of Al, Zn, Fe and CaCO3 into different test tubes.

    2. Add 5 ml of dilute NaOH to each tube. Note the change.

    B. Changes caused by acid effect

    1. Insert a piece of Cu, Zn, CaCO3 and KOH into different test tubes. Add 3 ml of dilute

    HCl to each tubes. Note the change and write the equation of reaction.

    2. Pour concentrated H2SO4 into a test tube then insert a piece of wood into it. Note the

    change.

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    C. Changes caused by heat effect

    By using the test tube clamp, heat a piece of magnesium in a bunsen flame. Repeat

    this experiment with Cu loops. Note the event that happen.

    V. POTENTIAL HAZARDS

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    VI. REPORT FORMAT

    Aa

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    Experiment 2 SEPARATION AND PURIFICATION OF

    SUBSTANCES

    I. OBJECTIVES

    To know the types of separation based on the physical and chemical properties.

    II. INTRODUCTION

    Mixtures are not unique to chemistry; we use and consume them on a daily basis. The

    beverages we drink each morning, the fuel we use in our automobiles, and the ground we

    walk on are mixtures. Very few materials we encounter are pure. Any material made up of

    two or more substances that are not chemically combined is a mixture.

    The isolation of pure components of a mixture requires the separation of one

    component from another. Chemists have developed techniques for doing this. These methods

    take advantage of the differences in physical properties of the components. The techniques to

    be demonstrated in this laboratory are the following:

    1. Sublimation. This involves heating a solid until it passes directly from the solid phase

    into the gaseous phase. The reverse process, when the vapor goes back to the solid phase

    without a liquid state in between, is called condensation or deposition. Some solids

    which sublime are iodine, caffeine, and paradichlorobenzene (mothballs).

    2. Extraction. This uses a solvent to selectively dissolve one component of the solid

    mixture. With this technique, a soluble solid can be separated from an insoluble solid.

    3. Decantation. This separates a liquid from an insoluble solid sediment by carefully

    pouring the liquid from the solid without disturbing the solid (Figure 2.1).

    4. Filtration. This separates a solid from a liquid through the use of a porous material as a

    filter. Paper, charcoal, or sand can serve as a filter. These materials allow the liquid to

    pass through but not the solid (see Figure 2.2 in the Procedure section).

    5. Evaporation. This is the process of heating a mixture in order to drive off, in the form of

    vapor, a volatile liquid, so as to make the remaining component dry.

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    Figure 2.1. Decantation

    Figure 2.2. Separation scheme

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    III. EQUIPMENT & CHEMICALS

    III.1.Equipment

    1. Test tube

    2. Filter paper

    3. Vaporizer bowl

    4. Mixer

    5. Drop straw

    6. Measurement glass 10 ml or 25 ml

    7. Wash bottle

    8. Bunsen

    9. Funnel

    10. Watch glass

    11. Beaker glass

    12. Scale

    13. Ni-Cr wire

    14. Clamp

    III.2. Chemicals

    1. KNO3

    2. Na2SO4

    3. Sodium Cobalt Nitrite

    4. Al(OH)3

    5. KOH 2 M

    6. KCNS

    7. Cu(NO3)2

    8. NH4Cl

    9. BaCl2

    10. Fe2O3

    11. Dilute HCl

    12. Distillated water

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    IV. PROCEDURES

    IV.1. Separation of substance based on physical properties

    IV.1.1. Dissolution and Filtration

    The purification or separation mixtures of solid substances and solid substances based

    on the solubility difference in substance of a particular solvent.

    1. Make a mixture substance with salt and lime with the weight ratio isdetermined by the

    assistant (%wt)

    2. Weigh the mass of filter paper

    3. Dissolute that mixture substance into warm water (200 cc), then write down the

    temperature of water, and stir it until the substances dissolve completely.

    4. Filter the substance that not soluble, then drying it and weigh it

    5. Calculate the mass percent of the salt that can separated before.Give a comment from

    your results of observation!

    IV.2.2.Crystallization

    The separation substance based on the solubility and temperature difference from two

    or more of substances.

    1. Add 10 ml of distillated water into test tube, then adding KNO3 2 M 3 ml into that test

    tube with little CuNO3 (1 spatula). Heating that mixture until soluble, then cooling it

    and filtering the crystal that form. Rinsing it with distillated wateruntil the color

    disappears.

    2. Dissolve a little crystal into the distillated waterand testing ion K with ion specific test.

    To another crystal, we do flame test.

    IV.1.3. Sublimation

    The separation of substances that have a high pressure on temperature basis below the

    melting point.

    1. Put a mixture of Na2SO4 and NH4Cl (2 grams each) into vaporizer bowl. Heating it

    slowly until white steam appears. Put watch glass on bowl, and continuing the heating

    until there are no white steam.

    2. Collect the white substances that cling on watch glass, then add 10 ml of water. White

    substances is divided into 2 parts :

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    18

    a. The part where NaCo(NO2)6 is added (sodium cobalt nitrite). Observed and write

    down that occurs!

    b. The part where BaCl2 is added (Barium Chloride). Observed and write down that

    occurs!

    IV.2. Separation of substance based on chemical properties

    Separation based on amphoteric substance

    1. Weigh Al(OH)3 and Fe2O3 (1 grams each)

    2. Put the mixture substance into beaker glass 250 ml, adding 15 ml of water and 25 ml

    of KOH 2 M, then heat up the solution and stir the solvent until Al(OH)3 soluble.

    3. Cool the solution and filtering it. Dissolve the sediment into HCl dilute and test it with

    KCNS. Observe what that happen!

    4. Add dilute HCl with drop by drop wise into the filtrate. Observe what that happen!

    V. POTENTIAL HAZARDS

    aa

    VI. QUESTIONS AND PROBLEMS

    1. Explain and write down the reaction of sublimation!

    2. Determine the percipates that occurs in the above experiment!

    VII. REPORT FORMAT

    aaaa

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    Experiment3 REACTIONS OF ACIDS AND BASES

    I. OBJECTIVES

    1. To identicifate acids and bases by investigate the pH of some solutions

    2. To know the influence of concentration to the solutions pH

    3. To calculate the concentration and the stochiometry of acids and bases

    II.INTRODUCTION

    We frequently encounter acids and bases in our daily life. Fruits, such as oranges,

    apples, etc., contain acids. Household ammonia, a cleaning agent, and Liquid Plumber are

    bases. Acids are compounds that can donate a proton (hydrogen ion). Bases are compounds

    that can accept a proton. This classification system was proposed simultaneously by Johannes

    Brnsted and Thomas Lowry in 1923, and it is known as the Brnsted-Lowry theory. Thus

    any proton donor is an acid, and a proton acceptor is a base.

    When HCl reacts with water

    HCl + H2O H3O+ + Cl

    HCl is an acid and H2O is a base because HCl donated a proton thereby becoming Cl, and

    water accepted a proton thereby becoming H3O+. In the reverse reaction (from right to left) the

    H3O+is an acid and Clis a base. As the arrow indicates, the equilibrium in this reaction lies far to the

    right. That is, out of every 1000 HCl molecules dissolved in water, 990 are converted to Cland only

    10 remain in the form of HCl at equilibrium. But H3O+ (hydronium ion) is also an acid and can

    donate a proton to the base, Cl. Why do hydronium ions not give up protons to Clwith equal ease

    and form more HCl? This is because different acids and bases have different strengths. HCl is a

    stronger acid than hydronium ion, and water is a stronger base than Cl.

    In the Brnsted-Lowry theory, every acidbase reaction creates its conjugate acidbase pair.

    In the above reaction HCl is an acid which, after giving up a proton,becomes a conjugate base, Cl.

    Similarly, water is a base which, after accepting a proton,becomes a conjugate acid, the hydronium

    ion.

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    Some acids can give up only one proton. These are monoprotic acids. Examples are

    HCl, HNO3, HCOOH , and CH3COOH. The hydrogens circled are the ones donated. Other

    acids yield two or three protons. These are called diprotic or triprotic acids. Examples are

    H2SO4, H2CO3, and H3PO4. However, in the Brnsted-Lowry theory, each acid is considered

    monoprotic, and a diprotic acid (such as carbonic acid) donates its protons in two distinct

    steps:

    1. H2CO3 + H2O H3O+ + HCO3

    2. HCO3 + H2O H3O

    + + CO32

    Thus the compound HCO3

    is a conjugate base in the first reaction and an acid in the

    second reaction. A compound that can act either as an acid or a base is called amphiprotic. In

    the self-ionization reaction

    H2O + H2O H3O+ + OH

    one water acts as an acid (proton donor) and the other as a base (proton acceptor). In

    pure water, the equilibrium lies far to the left, that is, only very few hydronium and hydroxyl

    ions are formed. In fact, only 1 x 107 moles of hydronium ion and 1 x 107 moles of

    hydroxide ion are found in one liter of water. The dissociation constant for the selfionization

    of water is

    This can be rewritten as

    Kw, the ion product of water, is still a constant because very few water molecules

    reacted to yield hydronium and hydroxide ions; hence the concentration of water essentially

    remained constant. At room temperature, the Kw has the value of

    Kw = 1 x 1014 = [1 x 107] [1 x 107

    This value of the ion product of water applies not only to pure water but to any

    aqueous (water) solution. This is very convenient because if we know the concentration of

    the hydronium ion, we automatically know the concentration of the hydroxide ion and vice

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    21

    versa. For example, if in a 0.01 M HCl solution HCl dissociates completely, the hydronium

    ion concentration is [H3O+] = 1 x 102M.This means that the [OH] is

    [OH] =Kw

    [H3O+]=

    1 x 1014

    1 x 102= 1 x 1012M

    To measure the strength of an aqueous acidic or basic solution, P. L. Sorensenintroduced the

    pH scale.

    pH = log[H3O+]

    In pure water, we have seen that the hydronium ion concentration is 1 x 107M. The

    logarithm of this is -7 and, thus, the pH of pure water is 7. Since water is an amphiprotic

    compound, pH 7 means a neutral solution. On the other hand, in a 0.01 M HCl solution

    (dissociating completely), we have [H3O+] = 1 x 102M. Thus its pH is 2. The pH scale

    shows that acidic solutions have a pH less than 7 and basic solutions have a pH greater than 7.

    The pH of a solution can be measured conveniently by special instruments called pH

    meters. All that must be done is to insert the electrodes of the pH meter into the

    solution to be measured and read the pH from a scale. pH of a solution can also be obtained,

    although less precisely, by using a pH indicator paper. The paper is impregnated with organic

    compounds that change their color at different pH values. The color shown by the paper is

    then compared with a color chart provided by the manufacturer.

    There are certain solutions that resist a change in the pH even when we add to them

    acids or bases. Such systems are called buffers. A mixture of a weak acid and its conjugate

    base usually forms a good buffer system. An example is carbonic acid, which is the most

    important buffer in our blood and maintains it close to pH 7.4. Buffers resist large changes in

    pH because of the Le Chatelier principle governing equilibrium conditions. In the carbonic

    acidbicarbonate (weak acidconjugate base) buffer system,

    H2CO3 + H2O H3O+ + HCO3

    any addition of an acid,H3O+, will shift the equilibrium to the left. Thus this reduces

    the hydronium ion concentration, returning it to the initial value so that it stays constant;

    hence the change in pH is small. If a base, OH, is added to such a buffer system, it will react

    with the H3O+ of the buffer. But the equilibrium then shifts to the right, replacing the reacted

    hydronium ions, hence again, the change in pH is small.

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

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    Buffers stabilize a solution at a certain pH. This depends on the nature of the buffer

    and its concentration. For example, the carbonic acidbicarbonate system has a pH of 6.37

    when the two ingredients are at equimolar concentration. A change in the concentration of the

    carbonic acid relative to its conjugate base can shift the pH of the buffer. The Henderson-

    Hasselbalch equation below gives the relationship between pH and concentration.

    pH = pKa + log[A]

    [HA]

    In this equation the pKa is the log Ka , where Ka is the dissociation constant of

    carbonic acid

    [HA] is the concentration of the acid and [A] is the concentration of the conjugate

    base. The pKa of the carbonic acidbicarbonate system is 6.37. When equimolar conditions

    exist, then [HA] = [A]. In this case, the second term in the Henderson-Hasselbalch equation

    is zero. This is so because [A]

    [HA]= 1, and the log 1=0. Thus at equimolar concentration of the

    acidconjugate base, the pH of the buffer equals the pKa; in the carbonic acidbicarbonate

    system this is 6.37. If, however, we have ten times more bicarbonate than carbonic acid,

    [A]

    [HA]= 10, then log 10=1 and the pH of the buffer will be

    III. EQUIPMENT & CHEMICALS

    III.1. Equipment

    1. 6 test tubes and its shelf

    2. Burette, stand with utility clamp

    3. Pipette, volumetric pipette, and graduated pipette

    4. Volumetric flask 100 ml

    5. Erlenmeyer 250 ml, beaker glass, glass stirring

    6. pH paper/pH universal

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    23

    III.2. Chemicals

    1. Some acids and bases, weak and strong

    2. Acids: HCl, HNO3, CH3COOH

    3. Bases: NaOH, BaOH2, Mg(OH)2 (or other bases)

    4. Indicator phenolphthalein

    5. Crystal NaOH

    IV. PROCEDURES

    IV.1.The Properties of Acids and Bases

    1. Ask you assistant to give you 6 acids and bases. Observe and note the color of the

    solutions.

    3. Take 5 ml of the solution into the test tube. Sign each solution with name L1 until L6.

    4. Take the pH paper, dip the edge into the solution. Be careful mot to hit your fingers.

    Dry the paper and note the color. Determine the pH of the solution by matching the

    color of the pH paper with the instructions in the pH papers box.

    5. Do the step A3 for all of the solutions given by the assistant. Note all of the solutions

    pH and give sign what solutions are acids and bases. Give basic description of what

    you use to distinguish acids and bases.

    6. Take one of the acids and bases solution above. Fill into the test tube of each solution 5

    ml. Give the sign a0 (acid) and b0 (bases). Perform a ratio of 1:1; 1:10; 1:100; and

    1:1000 dilutions. Give the name of each solution a1 until a4 for acids and b1 until b4 for

    bases.

    7. Measure the pH of each solution as step A2. Record the pH and fill the record into

    table accordance with the order of the concentration of the solution.

    8. Create a graph of the concentration and pH of the solution. What conclusion that you

    get from the experiment?

    IV.2. Acids and Bases Reaction

    1. Make a solution of 0.1 molar NaOH, HCland acetic acid as 100 ml each. Write the

    calculation and how to make the solutions.

    2. By using volumetric pipette, take 5 ml of 0,1 molar solution of HCl and put into

    Erlenmeyer. Then give 1-2 drops of phenolphthalein indicator. Observe and record the

    color.

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    24

    3. Fill NaOH solution into the burette and record the volume. Read the scale of the

    burette correctly.

    4. Perform titration of HCl solution by adding a little NaOH and whipped it at each

    addition. Stop the addition ofNaOH right at the time of the change of the solutions

    color. Record the volume of NaOH remaining in the burette.

    5. Write the acid-base reaction. Calculate the number of moles ofHClaccording to

    titrations data and compare the results with theoretical calculation (from the initial

    concentration and volume of HCl).

    6. Repeat the step 2 to 5 for acetic acid solution.

    V. POTENTIAL HAZARDS

    aa

    VI. QUESTIONS AND PROBLEMS

    1. What is the indicator of the acid-base titration? Explain how to select an indicator for

    titration.

    2. What is the difference of acids/bases strong and weak? Mention the ways to identify

    whether an acid and base is strong or weak.

    VII. REPORT FORMAT

    aa

  • Basic&Organic Chemistry Laboratory Chemical Engineering Department, Faculty of Engineering Universitas Indonesia

    25

    Experiment4 THE REACTION OF METALS WITH

    ACIDS

    I. OBJECTIVES

    1. Qualitative and quantitative analysis related with reactivity reaction between metals

    and acid.

    2. The used of data titration for stoichiometric reaction calculation.

    II. INTRODUCTION

    II.1. Reactions of acids with metals

    Acids react with most metals and a salt is produced. But unlike the reaction between

    acids and bases we don't get any water. Instead we get hydrogen gas.

    This is the general word equation for the reaction:

    metal + acid salt + hydrogen

    II.2. Salts

    The salt produced depends upon the metal and the acid. Here are two examples:

    zinc + sulphuric acid zinc sulphate + hydrogen

    magnesium + hydrochloric acid magnesium chloride + hydrogen

    It doesn't matter which metal or acid is used, if there is a reaction we always get

    hydrogen gas as well as the salt.

    II.3.The test for hydrogen

    There is a simple laboratory test to see if a gas is hydrogen. A lighted wooden splint

    goes pop if it is put into a test tube of hydrogen. This is because the flame ignites the

    hydrogen, which burns explosively to make a loud sound.

    II.4. Acids and hydrogen

    All acids contain hydrogen atoms. Apart from hydrochloric acid, this is not clear from

    their names, but you can tell they contain hydrogen from their chemical formulae. Remember

    that the chemical symbol for hydrogen is H.

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    III. EQUIPMENT & CHEMICALS

    III.1.Equipment

    1. Glass funnel and filter paper

    2. Five test tubes

    3. Five erlenmeyer flask 100ml and watch glass

    4. Burette, clamp, and balance

    5. Pipette, Volumetric pipette, and measuring cylinder

    6. Volumentric flask 50 ml

    III.2. Chemicals

    1. Metal powder Zn (zinc), Cu (copper), Fe (iron) and Al (aluminum)

    2. 6 M HCI andNaOH solution

    3. Methyl orangeindicator

    IV. PROCEDURES

    IV.1. Qualitative Observation

    1. Provide 4 pieces of test tubes, and fill each tube with 6M HCl solution 5ml. Label it

    S1 s/d S4.

    2. Weigh each 0,1 gr metals Zn, Fe, Cu and Al. Then, insert those metals to the

    test tubes Sl s/d S4. Observe and note the changes happened.

    3. If the metals reactivity can be seen from the amount of gas formed, order the metals

    reactivity based on your observation!

    4. Write down the reaction equation from this experiment and suggest an experiment to test

    what kind of gas formed on the reaction above.

    IV.2. Quantitative Observation

    1. Provide 5 pieces of clean erlenmeyer flask 100 ml. Label itSl s/d S5.

    2. Fill each erlenmeyer with 6M HCl 10 ml (use volumetric pipette 10ml, measure it

    correctly), then close it with watch glass. Calculate the mole of HCl, and write down

    the aswer.

    3. Insert Zn, Fe, Cu and Al metals 0,2 gr each into erlenmeyer S1 s/d S4 . Solution in

    erlenmeyer S5 will be reacted with nothing.

    4. Note when the metals reacted, and let the reaction happened for 30-40 minutes.

    (determined by the assistant).

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    5. After the reaction finish, separate the metals from the solution with the filtration process (wet

    the filter paper with distillated watert before use it in filtration process).

    6. Take the solution from erlenmeyer Sl s/d S5 2 ml each, and add 1-2 drops of methyl

    orangeindicator. Observe and write down the color.

    7. Titrate the solution with 1.0 M NaOH solution. Calculate the total amount of mole

    HCl after reaction.

    8. Calculate the HCl conversion with the formula below:

    (Amount of mole HCl reacted)

    (Amount of mole HCl before the reaction) 100%

    9. Make a table/graph between the type of metals vs %-HCl conversion. Order the

    metals based on their reactivity, and compare this result with the result from

    experiment A.

    V. POTENTIAL HAZARDS

    aaa

    VI. QUESTIONS AND PROBLEMS

    1. Is there any effect from the location of these metals in periodic table and their

    reactivity to react with acid? Explain!

    2. What factor affect the rate of reaction in general as long as you know?

    VI. REPORT FORMAT

    aaaa

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    Experiment5 WATER CRYSTALS

    I. OBJECTIVES

    1. To learn dehidration activity and hidration of a solid containing water crystals.

    2. To calculate the empiric formula of water crystals.

    II. INTRODUCTION

    aaa

    III. EQUIPMENT & CHEMICALS

    III.1. Equipment

    1. Threepyrextest tubes

    2. Droplet pipette and wood clamp

    3. Three vaporazer cup

    4. Bunsen burner

    III.2. Chemicals

    1. Solid materials containing water crystals:CuSO4.XH2O,

    MgSO4.XH2O,CaCl2.XH2O.

    2. Distillated water

    IV. PROCEDURES

    IV.1. Qualitative Observation

    1. Ask a assistant 3 kinds of solid materials containing crystalline water. Observe and

    write down the name of the substance and their colors.

    2. Insert those substance into a pyrex test tube each. Label it .

    3. Use a wood clamp to hold the test tube, then heat the substance in the tube on the

    bunsen burner. Observe and write down the changes happened.

    4. Then, drop a water into the test tube. Obseve and write down the changes

    happened.

    5. Write down the reaction equation, all of the heating and watter addition activity.

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    Explain those equation and the difference between those substance based on your

    observation.

    IV.2. Quantitavie Observation

    1. Provide3 piecesof ceramicbowls(evaporator. Weighand write down

    theweightcarefully.

    2. Insert solids substance containing crystalline water into the third cup, and write down

    the weight. Determine the weight of the substance

    3. Heat the cup containing sample until they change color just as color samples of

    uniform / homogeneous (color sample has changed all of the colors before

    warming),stop heating and immidiately weigh carefully weighed.

    4. Calculate the weight loss after heating. If weight loss is showing the amount of water

    contained in the crystal sample, determine the empiric formula of crystal water, then

    compare with the theoritical and empiric formula.

    5. Try this experiment for three different sample and show the similiarities and

    differences of your observations

    V. POTENTIAL HAZARDS

    aaa

    VI. QUESTIONS AND PROBLEMS

    1. Write down the name, empiric formula, color, and physical properties from 3 kind

    of solid substance containing crystal water.

    2. Give an example in chemical engineering industries which use dehydration and

    hydration process.

    VI. REPORT FORMAT

    aaaa

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    Experiment 6 IDENTIFICATION OF HYDROCARBON

    I. OBJECTIVES

    To identify several properties of hydrocarbon.

    II. INTRODUCTION

    Numerous numbers of organic compounds is made by the carbon atoms which attract

    one another and other molecule that are able to make bond with known carbon group. To

    make it simple, we can say that hydrocarbon is a compound with bond between hydrogen and

    carbon only.

    Hydrocarbon has many bonds, but can be grouped by their unique characters where

    these structures are also suit with the general chemical reactivity. Then every group can be

    grouped from its structure or reactivity. In this test, practitioner will test the chemical

    reactivity from saturated, unsaturated, and aromatic hydrocarbon.

    II.1. Hydrocarbon Structure

    Hydrocarbon can be considered saturated if there is maximum number of hydrogen

    which is bonded to carbon. It is happen if the carbons bonded as single bond or it is called as

    sigma bond (). Ethane is an example for saturated hydrocarbon with these criteria.

    Unsaturated hydrocarbon has less number of hydrogen which can make bond from its

    maximum number. This compound must have double bond so that the total number of

    covalent bond is four. Ethylene and acetylene are examples for this compound.

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    Double carbon bonds from ethylene consist of one bond which is the same with

    saturated hydrocarbon and one pi bond (). Both of them can form double bond, while

    acetylene has triple bond with one bond and two bonds.

    Aromatic hydrocarbon has unique bond within its carbon which is difficult to explain.

    In benzene, one of aromatic hydrocarbon, all of the carbon bonds are identical (six bonds).

    Two type of benzene bonds, a and b, have single and double bonds which are varied.

    But, both of them represent a different molecule. Structure (c), using circle inside the

    hexagon, can be accepted. The circle represents the six electrons which are distributed evenly

    at the aromatic bond at six carbon atoms. The bonds which are represented by the

    hexagonal side are bond. Structure (c) can be used to represent all kind of carbon bonds

    inside the benzene correctly.

    II.2. Reactivity of Hydrocarbon

    The bond from saturated bond (alkane) is very stable so it is not reactive. At high

    temperature, saturated hydrocarbon can react with oxygen (combustion). From this reaction,

    carbon bonds are broken and the products are carbon dioxide and water. If the combustion is

    not efficient, then carbon monoxide or even single carbon (soot) can be produced. But,

    generally, saturated hydrocarbon is combusted more efficiently than other types of

    hydrocarbon.

    The hydrogen-carbon bond from alkane can be replaced by halogen. General reaction

    for bromine is:

    Look at the equation, HBr is a product from the reaction. To react with halogen, we

    need heat or light energy.

    The bond from unsaturated hydrocarbon (alkene and alkyne) is reactive and it is

    easier for additional reaction to happen. In this reaction, a molecule like bromine forms two

    single bonds of carbon-bromine which is in one bond energy level. Ethylene reacts with

    bromine to form 1,2-dibromothane.

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    This reaction happens in room temperature. As the product, a character of brownish

    red from bromine is disappeared. We should also pay attention to the reaction that there is no

    HBr produced like in the substitution reaction for saturated hydrocarbon. Acetylene has two

    bonds which occur additional reaction:

    The bond from aromatic compound is hold out in the reaction. Even for saturated

    group which make bond with benzene ring can be attacked by oxidizing agents with a very

    large energy. The product which is produced when single group alkyl bonded with benzene

    ring is benzoic acid.

    Hydrogen atom from benzene can be substituted by bromine, but it needs catalyst Fe.

    Look that the following reaction is a substitution reaction and HBr is produced.

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    III. EQUIPMENT & CHEMICALS

    III.1. Equipment

    1. Testtube 10 x 75 mm

    2. Testtube 16 x 150 mm

    3. Generator acetylene

    4. Pipette

    5. Watch glass

    6. Test tube rack

    III.2. Chemicals

    1. Heptane

    2. Octene

    3. Toluene

    4. Xylene

    5. Butanol

    6. Carbon tetrachloride

    7. 1% vol bromine in carbon tetrachloride

    8. Iron tack

    9. 1% wt potassium permanganate solution

    10. Unknown sample

    11. Calcium carbide

    12. Litmus paper

    IV. PROCEDURES

    Caution: all organic waste must be thrown at the right place.

    Note:

    5. Do all the following experiments below.

    6. Experiment A until D use three types of hydrocarbon: heptane, 1-octene, and toluene.

    Use clean and dry test tubes for all reactions. The structure for the three compounds

    are :

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    7. Most alkanes contain alkene as pollutant. To clean the pollutant, alkane is mixed with

    H2SO4 with the ratio alkane: H2SO4 = 3:1. It will form a layer, where the lower layer

    which is darker (H2SO4) is separated. The remaining alkane layer is treated again with

    H2SO4 until it do not form anymore darker layer. Then, alkane is washed by water. (be

    careful with H2SO4 solution, can be performed only by expert).

    IV.1. Solubility of Hydrocarbon

    1. Shake slowly the 0.5 mL heptane with 5 mL water solvent in test tube 16x150 mm to

    test its solubility. Write down your observation.

    2. Repeat step 1 with other samples: 1-Octene and toluene, each with same ratio.

    3. Change the solvent with 1-butanol and ligroin (mix of alkane), repeat step 1 and step 2

    with same ratio.

    IV.2. Flammability of Hydrocarbon

    Attention: Hydrocarbon is highly flammable, and its vapor is very explosive in air. Be

    careful with the flame. Do not add the quantity of the hydrocarbon as it has already been set

    in this experiment.

    1. Expel three drops of one type of hydrocarbon sample on the watch glass, by using

    matches/lighter, light the hydrocarbon.

    2. Observe the type and color of the flame, carbon in the flame and the remaining

    residue.

    3. Repeat the above steps for other two hydrocarbons.

    4. Write down your observation.

    IV.3. Effect of Bromine in Carbon Tetrachloride

    1. Put 1 mL bromine in carbon tetrachloride in a small test tube.

    2. Add 10-20 drops of hydrocarbon sample, observe the change of colour.

    3. If there is no colour change after 20 drops, add iron tack, and wait for 5 minutes.

    4. If there is still no colour change, heat the solution in a hot water bath for 15-20

    minutes.

    5. To test if there is hydrogen bromide, place blue litmus paper at the tip of the test tube.

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    6. Repeat the experiment with two other sample of hydrocarbon.

    7. Write down your observation.

    IV.4. Reaction with Potassium Permanganate

    1. Place 1 mL sample of hydrocarbon in a small test tube.

    2. Add 3 drops of 1% potassium permanganate solution.

    3. Shake the test tube, observe all the changes that happen. How long does it need for the

    changes to start?

    4. Repeat with another sample of hydrocarbon.

    5. Write down your observation.

    IV.5. Grouping The Substance

    1. Get unknown samples from your laboratory assistant.

    2. Do the tests to group the samples to saturated, unsaturated, and aromatic.

    IV.6. Preparation and Chemical Properties of Acetylene

    1. Pay attention to the instrumentation of acetylene consists of a dry 250 mL bottle with

    two rubber stopper, a dropping line, glass tubing, and appropriate rubber.

    2. Put some pieces of calcium carbide (CaC2) inside the dry bottle.

    3. Add the water carefully and slowly to a certain degree to form acetylene gas.

    4. To dry the test tube 16x150 mm with 10 drops of 1% bromine in carbon tetrachloride

    solution, add about 3 mL carbon tetrachloride. Flow the acetylene to the solution.

    Observe the changes that happen.

    5. For the 16x150 mm test tube which has 3 drops of 1% potassium permanganate, add

    about 3 mL water. Flow the acetylene to the solution until the colour of permanganate

    is disappeared. If the reaction is slow, shake and continue the flow of acetylene.

    Repeat until the colour disappears. Observe the changes that happen.

    6. Write down your observation.

    V. POTENTIAL HAZARDS

    Flame risk from heating chemical. Use gloves when heating the chemicals with

    Bunsen or with water bath.

    Heptane

    - Breathing vapors may cause drowsiness and dizziness. Causes eye, skin, and

    respiratory tract irritation. Aspiration hazard if swallowed. Can enter lungs and

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    cause damage. Dangerous for the environment.

    - Wear protective gloves,clothing and masker to prevent exposure.

    1-octene

    - Causes eye, skin, and respiratory tract irritation. Toxic to aquatic organisms, may

    cause long-term adverse effects in the aquatic environment. Aspiration hazard if

    swallowed. Can enter lungs and cause damage. May cause central nervous system

    effects.

    - Wear protective eyeglass, gloves,clothing to prevent exposure.

    Toluene

    - Causes eye irritation. Prolonged or repeated contact can defat the skin and lead to

    irritation and/or dermatitis. Inhalation causes headaches, dizziness, drowsiness,

    nausea, and respiratory irritation. If swallowed, causes headaches, dizziness,

    drowsiness and nausea, and may lead to unconsciousness. Harmful or fatal if liquid

    is aspirated into lungs. Danger! Contains Benzene. Cancer hazard. Can cause blood

    disorders. Harmful when absorbed through the skin.

    - Wear chemical goggles, protective gloves, and clothing to prevent exposure.

    Xylene

    - Hazardous in case of skin contact (irritant, permeator), of eye contact (irritant), of

    ingestion, of inhalation.

    - Wear splash goggles, lab coat, and gloves.

    1-butanol

    - Causes severe eye irritation and possible eye injury.Breathing vapors may cause

    drowsiness and dizziness. Causes skin and respiratory tract irritation. May be

    harmful if swallowed. Aspiration hazard if swallowed. Can enter lungs and cause

    damage. May cause central nervous system depression.

    - Wear chemical splash goggles, protective gloves, and clothing to prevent exposure.

    Carbon tetrachloride

    - May be fatal if inhaled, absorbed through the skin or swallowed. Causes eye, skin,

    and respiratory tract irritation. Aspiration hazard if swallowed. Can enter lungs and

    cause damage. Cancer suspect agent. May cause liver and kidney damage. May

    cause central nervous system effects. This is a CFC substance which destroys

    ozone in the upper atmosphere. Destruction of the ozone layer can lead to increased

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    ultraviolet radiation which, with excess exposure to sunlight, can lead to an

    increase in skin cancer and eye cataracts. Marine pollutant.

    - Wear chemical safety goggles, protective gloves, and clothing to prevent exposure.

    Bromine

    - Strong oxidizer. Contact with other material may cause a fire. Corrosive. Causes

    eye and skin burns. May cause severe respiratory tract irritation with possible burns.

    May cause severe digestive tract irritation with possible burns. Lachrymator

    (substance which increases the flow of tears). May cause central nervous system

    effects. May cause cardiac disturbances. May cause liver and kidney damage.

    - Wear chemical goggles and face shield, protective gloves, and clothing to prevent

    exposure.

    Calcium carbide

    - Dust may irritate respiration system, serious burns may occur because chemical

    reacts quickly with water to form acetylene & calcium hydroxide in vigorously

    exothermic reaction. Acetylene may displacing oxygen.

    - Wear chemical safety goggles, protective gloves, and clothing to prevent skin

    exposure.

    VI. QUESTIONS AND PROBLEMS

    Give the products these following reactions:

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    VII. REPORT FORMAT

    Name ______________ Date ______________

    Partner ______________ Lab. Assistant ______________

    REPORT SHEET

    Solubility of Hydrocarbon

    Sample Solubility

    Water 1-butanol Ligroin

    heptane

    1-octene

    toluene

    Flammability of Hydrocarbon

    Sample Flammability

    Type Color Carbon Total Residue

    heptane

    1-octene

    toluene

    Effect of Bromine in Carbon Tetrachloride

    Sample Change of Color

    10-20 drops Iron Tack Heating Blue Litmus Paper

    heptane

    1-octene

    toluene

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    Name ______________ Date ______________

    Partner ______________ Lab. Assistant ______________

    REPORT SHEET

    Reaction with Potassium Permanganate

    Sample Reaction

    3 drops After shake Time

    heptane

    1-octene

    toluene

    Grouping The Substance

    Sample Grouping

    Saturated Unsaturated Aromatic

    1

    2

    3

    Preparation and Chemical Properties of Acetylene

    Sample Change

    carbon tetrachloride Water Shake

    carbon tetrachloride - -

    potassium permanganate -

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    Experiment 7 IDENTIFICATION OF ALCOHOL

    I. OBJECTIVES

    To identify several properties of alcohol.

    II. INTRODUCTION

    Alcohol can be said as organic solvent which is analog to water. In alcohol, hydroxyl

    group (-OH) is attached to saturated carbon not at the hydrogen atom as in water. The

    hydroxyl group makes physical and chemical properties very different with hydrocarbon.

    Structure from hydroxyl group which is strongly affected character of alcohol is a polar bond

    between hydrogen-oxygen and a pair of electrons from the oxygen.

    Some chemical differences from alcohol depends on the alkyl group structure. One

    important thing is how many carbon atom which is bonded with the C-OH group. Primer,

    secondary, and tertiary alcohol have 1,2, and 3 carbon group consecutively, which is attached

    at the carbon atom bonded to oxygen atom.

    Hydroxyl group from alcohol can make hydrogen bond with water. That is why,

    alcohol is soluble in water than in hydrocarbon. All alcohol with low molecular weight is

    completely soluble in water, and the solubility of high molecular weight is more likely to

    alkanes solubility. As the size of alkyl group increase, the polar hydroxyl group will give

    less contribution to physical properties.

    Proton from water molecule is more acidic than proton from hydroxyl group. That is

    why proton from hydroxyl group can only be neutralized by strong alkaline.

    Proton from hydroxyl group from water can be reduces by active metal and produces

    hydrogen gas. This reaction is between active metal and water.

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    Rate of this reaction depends on the alcohol acidity. The most acidic component will

    be the most reactive agent to sodium.

    Hydroxyl group from alcohol can be replaced by other groups such as halogen. The

    rate of reaction depends on the structure of alkyl group. The replacement of hydroxyl group

    from chlorine group can be done with some reagent. One of the example is Lucas reagent

    which consists of ZnCl2 and HCl.

    For tertiary alcohol, the reaction is very fast in room temperature. Secondary alcohol

    reacts in 5-10 minutes. Primary alcohol can react after hours in room temperature. Because

    alkyl chloride is not soluble in Lucas reagent, then the turbidity means that the reaction has

    occurred. Time needed to start the reaction indicates the type of structure in alcohol.

    Primary, secondary, and tertiary alcohols give different reaction to oxidizing agents.

    Type of oxidizing agent which is typically used is sodium dichromate (Na2Cr2O7) in dilute

    sulphate acid solution.

    Chromium is reduced to Cr3+ in the reaction. Dichromate solution is yellowish orange,

    while Cr3+ is green. Therefore, the alcohol oxidation by potassium dichromate is indicated by

    the change of colour from chromium species.

    The structure of alcohol below reacts continuously with iodine and NaOH to produce

    iodoform, yellow solid.

    This reaction can be used to characterize the structure of alcohol.

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    III. EQUIPMENT & CHEMICALS

    III.1. Equipment

    1. Test tube 10x75 mm

    2. Test tube 16x150 mm

    3. Beaker glass

    4. Pipettes

    5. Test tube rack

    III.2. Chemicals

    1. Methanol

    2. Ethanol

    3. 1-propanol

    4. 2-propanol

    5. 1-butanol

    6. 2-butanol

    7. 2-methyl-2-propanol

    8. 1-pentanol

    9. 1-octanol

    10. 1% Sodium dicromate solution (Na2Cr2O7 . 2H2O)

    11. 1M NaOH solution

    12. 6M HCl solution

    13. Iodine-Potassium iodide solution

    14. Lucas reagent

    IV. PROCEDURES

    IV.1. The Solubility of Alcohol in Water

    1. Put 1 ml of water in small test tube.

    2. Add some drops of ethanol while shaking until it does not soluble anymore or until

    the volume is twice from initial volume of water.

    3. Repeat the test with another alcohol (1-butanol, 2-butanol, 2-methyl-2-propanol, 1-

    pentanol, and 1octanol).

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    4. Characterize each alcohol: soluble, a litte soluble, or totally soluble. Write down on

    your report.

    IV.2. Reactivity of Alcohol with Sodium

    1. Your laboratory assistant will react sodium metal with methanol, ethanol, 1-propanol,

    2-propanol, and 2-methyl-2-propanol.

    2. Write down your observation in report, write down the chemical equation from these

    reactions.

    3. Put the level of acidity of alcohol in order from their O-H bonds.

    IV.3. Lucas Test

    1. Put 1 ml of 1-butanol in 16 x 150 mm test tube, add Lucas reagent.

    2. Close the test tube, mix the solution until it is soluble by shaking. Settle down in room

    temperature.

    3. Observe what happens after 5 minutes and after 30 minutes.

    4. Repeat the test with other samples: 2-butanol and 2-methyl-2-propanol.

    5. Write down your observation and write down the chemical equation from these

    reactions.

    6. If there is no reaction, mark with NR.

    IV.4. Oxidizing Alcohol

    1. Put 1 ml of alcohol samples and add 10 drops of HCl 6 M in test tubes.

    2. Add 1 drop of 10% Na2Cr2O7 solution and mix them well.

    3. Look and observe the change of colour.

    IV.5. Iodoform Reaction

    1. Add 4 drops of 1-propanol in 1 mL of methanol and 1 mL of water.

    2. Add 2 ml of NaOH 3M solution.

    3. Add drop by drop the I2-KI solution until yellow solid forms, CHI3 , or until the

    colour is brown after the mixing at least 2 minutes.

    4. Settle down the test tube for 5 minutes, observe what happens.

    5. Repeat the test by changing 1propanol with 2-propanol, 2-butanol, and 2-methyl-2-

    propanol.

    6. Write down your observation.

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    V. POTENTIAL HAZARDS

    Methanol

    - Toxic by ingestion and inhalation. Can be toxic by skin absorption.Affects central

    nervous system, especially optic nerve.Causes dizziness, nausea, muscle weakness,

    narcosis, respiratory failure.Prolonged or repeated skin contact may cause

    irritation.

    - Wear safety glasses, protective clothing and masker to prevent exposure

    Ethanol

    - Flammable liquid and vapor. Cause severe eye irritation and moderate skin

    irritation.

    - Wear protective clothing and masker to prevent exposure.

    1-propanol

    - May cause eye and skin irritation. May be harmful if swallowed. May cause

    respiratory tract irritation. May cause central nervous system depression. May

    cause dermatitis. Hygroscopic (absorbs moisture from the air).

    - Wear chemical goggles , protective clothing and masker to prevent exposure

    2-propanol

    - May cause central nervous system depression. May form explosive

    peroxides.Hygroscopic (absorbs moisture from the air). Causes respiratory tract

    irritation. Aspiration hazard if swallowed. Can enter lungs and cause damage. This

    material has been reported to be susceptible to autoxidation and therefore should

    be classified as peroxidizable. Causes eye irritation. Breathing vapors may cause

    drowsiness and dizziness. Prolonged or repeated contact causes defatting of the

    skin with irritation, dryness, and cracking.

    - Wear chemical goggles , protective clothing and masker to prevent exposure

    1-butanol

    - Causes severe eye irritation and possible eye injury.Breathing vapors may cause

    drowsiness and dizziness. Causes skin and respiratory tract irritation. May be

    harmful if swallowed. Aspiration hazard if swallowed. Can enter lungs and cause

    damage. May cause central nervous system depression.

    - Wear chemical splash goggles, protective gloves, and clothing to prevent exposure.

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    2-butanol

    - Breathing vapors may cause drowsiness and dizziness. Causes eye and respiratory

    tract irritation. May form explosive peroxides.

    - Wear chemical splash goggles, protective gloves, and clothing to prevent exposure.

    1-pentanol

    - Hygroscopic (absorbs moisture from the air). May cause eye irritation. May cause

    irritation of the digestive tract. May cause central nervous system depression. May

    cause burning sensations, coughing, wheezing, laryngitis, shortness of breath and

    headache. Harmful if inhaled.

    - Wear protective gloves, and clothing to prevent exposure.

    1-octanol

    - Causes eye and skin irritation.May cause respiratory tract irritation. May cause

    central nervous system depression.

    - Wear chemical splash goggles, protective gloves, and clothing to prevent exposure.

    Sodium dicromate solution (Na2Cr2O7 . 2H2O)

    - Potentially fatal if swallowed, harmful on contact with the skin, respiratory tract

    burns, skin burns, eye burns, mucous membrane burns, allergic reactions, cancer

    hazard (in humans)

    - Wear chemical goggles , protective gloves, and clothing to prevent exposure.

    NaOH solution

    - Mucous membrane irritant. Skin: severe irritation, sensitization, dermatitis &

    burns. Eyes: irritation,conjunctivitis& burns. Ingestion: damage to mucous

    membranes or tissues.

    - Wear protective gloves, and clothing to prevent exposure.

    HCl solution

    - Corrosive to skin, eyes, nose mucous membranes, respiratory & gastrointestinal

    tract. Inhalation:respiratory tract irritation/infection. Severe & fatal

    gastrointestinal burns w/necrosis. Severe burns to eyes & blindness. Changes in

    pulmonary function, chronic bronchitis,dermatitis, tooth erosion, & conjunctivitis.

    - Wear splash chemical goggles, protective gloves, and clothing to prevent

    exposure.

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    Iodine-Potassium iodide solution

    - May cause respiratory tract irritation. May cause skin irritation. May cause eye

    irritation. May cause digestive tract irritation.

    - Wear chemical safety goggles , protective gloves, and clothing to prevent

    exposure.

    VI. QUESTIONS AND PROBLEMS

    1. 1,2-Hexanediol is very soluble in water, while 1-hexanol is not soluble. Explain the

    reasons.

    2. A lab researcher has 4 compounds (a, b, c, d) with chemical formula C4H10O. All the

    compounds react with sodium and free hydrogen. In Lucas test, compound d reacts

    very fast b reacts after heated, while a and c react but very slow. Write down the

    structure of b and d! What is the possible structure of a and c?

    3. A compound with formula C3H8O does not react with sodium, Lucas reagent, or

    sodium dichromate solution. Write down the structure. Explain the character of the

    not reactive compound!

    4. There are 8 isomeric alcohol with formula C5H12O. Only two of them react with

    iodoform test. Write down the structure of the two compounds.

    5. Write down the products from the reactions below, if there is no reaction happens,

    write NR:

    a.

    b.

    c.

    d.

    e.

    f.

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    g.

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    VII. REPORT FORMAT

    Name ______________ Date ______________

    Partner ______________ Lab. Assistant ______________

    REPORT SHEET

    The Solubility of Alcohol in Water

    Sample Characterize

    Soluble Little Soluble Totally Soluble

    ethanol

    1-butanol

    2-butanol

    2-methyl-2-propanol

    1-pentanol

    1octanol

    Reactivity of Alcohol with Sodium

    Sample Reactivity

    Change Chemical Equation Level of Acidity OH-Bond

    methanol

    ethanol

    1-propanol

    2-propanol

    2-methyl-2-propanol

    Lucas Test

    Sample Lucas Test

    5 minute 10 minute Chemical Equation

    1-butanol

    2- butanol

    2-methyl-2-propanol

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    Name ______________ Date ______________

    Partner ______________ Lab. Assistant ______________

    REPORT SHEET

    Oxidizing Alcohol

    Iodoform Reaction

    Sample Color Change

    1 drop Shake

    methanol

    ethanol

    1-propanol

    2- propanol

    1-butanol

    2-butanol

    2-methyl-2-propanol

    1-pentanol

    1octanol

    Sample Amount I2-KI Color Change

    2 minutes 5 minutes

    methanol

    1-propanol

    2- propanol

    2-butanol

    2-methyl-2-propanol

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    Experiment 8 LIPID, OIL, SOAP, AND DETERGENT

    I. OBJECTIVES

    1. To understand several properties of oil and lipid

    2. To understand the soap-making procedures

    3. To know the existence of phosphate in commercial detergent

    II. INTRODUCTION

    Triglyceride, one kind of lipid, is ester from alcohol glycerol and long chain

    carboxylic acid.

    Triglyceride consists of acid with 8 to 12 carbon atom and mix of different types of

    acid. If most of the acid is not saturated, then glycerides will be liquid and classified as oil.

    Glycerides which have more saturated acid will have higher melting point and classified as

    lipid/fat.

    Hydrolysis of lipid or oil with base will produce glycerol and salt from the acid, it is

    known as saponification. Soap is salts from long chained carboxylic acid. Sodium and

    potassium salts are water soluble, while salts from magnesium, calcium, and iron are not

    water soluble.

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    Detergent is salts from aryl sulfonates or alkyl sulfates.

    Since calcium salts from aryl sulfonate and alkyl sulfate are water soluble, detergent

    is usually used in hard water, while soap will produce not soluble precipitate.

    Every year, Americans use millions kilogram of detergent to wash clothes or other

    things. Nearly every gram from detergent flows to lake or river. Most of laundry products

    contain phosphate which will make algae fertile in the water. Phosphate act as fertilizer to

    algae in the same form as phosphate when it make plants or grass fertile in garden. Algae

    consume dissolved oxygen in water in a large number. Concentration of dissolved oxygen

    will reduce so it be difficult for the life of fishes or other sea animal, hence, it will disturb

    ecosystem equilibrium.

    In this experiment, commercial detergent will be tested to know the existence of

    phosphate in it. The basic of this reaction is chemical reaction between phosphate anion and

    molybdate anion in acid solution.

    Ammonium molybdate solution, (NH4)6Mo7O24, is added to former acidic solution. If

    the sample contains phosphate anion, precipitate of ammonium phosphomolybdate

    (NH4)3PMo12O40will be well separate and light yellow solid will form.

    In this experiment, practitioners will be asked to bring a few sample of liquid or

    powder detergent. Make sure to check the label to determine whether the product contain

    phosphate. The sample will be tested with other practitioners samples to know whether there

    is phosphate or not.

    III. EQUIPMENT & CHEMICALS

    III.1. Equipment

    1. 16 x 150 mm test tube

    2. 10 x 75 mm test tube

    3. Reflux instrument

    4. Pipettes

    5. Glass stirring rod

    6. Beaker glass

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    III.2. Chemicals

    1. Cotton seed oil

    2. Hexane

    3. Carbontetrachloride

    4. 5% Bromine in carbontetrachloride solution

    5. Ethanol 95%

    6. NaOH solution

    7. High concentration of HCl solution

    8. A piece of soap

    9. Calcium chloride 0.1 M

    10. Magnesium chloride 0.1 M

    11. Iron (III) chloride 0.1 M

    12. Ammonium molybdate solution 0.2 M

    13. Nitric acid 6M

    14. Litmus paper or pH indicator paper

    15. Mineral oil

    IV. PROCEDURES

    IV.1. The Solubility of Cotton Seed Oil

    1. Put 0.5 mL (about 10 drops) cotton seed oil in each four 16x150 mm test tubes.

    2. Add 1 mL of water to the first tube, 1 mLof ethanol to the second tube, 1 mL of

    hexane to the third tube and 1 mL carbon tetrachloride to the fourth tube.

    3. Shake the test tubes, write down the solubility of each solution in the test tube.

    4. Add 5 mL of additional solvent.

    5. Shake each tube strongly, observe if the oil is soluble now.

    6. Write down your observation.

    IV.2. Unsaturated Triglyceride

    1. Use 2 mL of the solution between carbon tetrachloride and cotton seed oil which has

    been done in experiment A for this experiment.

    2. Add drop by drop 5% Bromine in carbon tetrachloride solution.

    3. Calculate the amount of drops needed to produce bromine color effect of the solution.

    4. Put 0.1 g of Crisco into 1 mL of carbon tetrachloride.

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    5. Repeat step 2 and 3.

    6. Write down your observation.

    IV.3. Soap

    Attention: Sodium hydroxide is caustic compound, do not touch this compound. Wash your

    hands as soon as you feel soapy. Sodium hydroxide can cause eye irritation and

    blindness. Clean up the contaminated equipment.

    IV.3.1. Preparation

    1. Fuse 5 g of sodium hydroxide into 10 mL of distillate water and into 25 mL ethanol in

    125 mL Erlenmeyer flask, put 5 g of triglyceride into the reflux flask.

    2. Add some boiling chips into the flask.

    3. Prepare the reflux instrument as it is shown in Picture 14. Ask your assistant to check

    your tool.

    4. Reflux the flask content for about 30 minutes or until the solution becomes pure and

    homogen.

    5. Move the soapy solution from heat, cool the flask and add about 80 mL of high

    concentrated sodium chloride solution.

    6. Shake the solution comprehensively and collect precipitated soap with the absorb

    filtration.

    IV.3.2. Equipment

    1. Prepare 1 g of soap solution (from the previous result of reflux) in 50 mL boiling

    distillate water.

    2. Prepare the same solution with commercial soap and detergent.

    IV.3.3. Alkaline Characteristic

    1. Test the pH from each solution with Litmus paper.

    2. Write down your observation.

    IV.3.4. Emulsion Characteristic

    1. Place 3 drops mineral oil to each four test tubes.

    2. Put in 5 mL of distillation water to the first tube, 5 mL soap solution (experiment

    result) to the second tube, 5 mL commercial soap to the third tube and 5 mL detergent

    solution to the fourth tube.

    3. Shake each tube for a minute.

    4. Write down your observation.

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    IV.3.5. The Effect of Metal Salt

    1. Put 5 mL of your soap solution experiment to each three test tubes.

    2. Add2 mLof Calcium chloride 0.1 M to the first tube, Magnesium chloride 0.1 M to

    the second tube and Iron (III) chloride 0.1 M to the third tube.

    3. Write down your observation.

    4. Repeat this experiment with commercial soap and detergent solution.

    IV.4. Phosphate Qualitative Test in Detergent

    1. Phosphate test is very sensitive. Therefore, wash your test tube until clean or you

    better use other new test tube.

    2. Add about 60 mg phosphate (like a grain of hulled rice) to the test tube.

    3. Add 8 drops of HNO3 6 M. Detergent that contains carbonate will cause foaming

    when HNO3 is added. If this happens, keep up adding drop by drop of HNO3 until the

    foam is not formed. Then, add again 8 drops of HNO3.

    4. If the detergent is in liquid form then use about 15-20 drops in this experiment.

    5. Using the magnetic stirrer, mix the solution smoothly.

    6. Add 2 drops of ammonium molybdate solution 0.2 M and heat the tube in hot water

    for about 5 minutes.

    7. If it contains phosphate, yellow precipitate will appear.

    V. POTENTIAL HAZARDS

    Cotton seed oil

    - May cause irritation. This is expected to be a low hazard for usual industrial

    handling.

    - Wear appropriate protective eyeglasses, protective gloves, and protective clothing

    to prevent skin exposure.

    Hexane

    - Extremely flammable liquid and vapor. Vapor may cause flash fire. Possible risk

    of impaired fertility. Breathing vapors may cause drowsiness and dizziness.

    Dangerous for the environment. May cause nervous system effects.

    - Wear appropriate protective eyeglasses, protective gloves, and protective clothing

    to prevent skin exposure

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    Carbontetrachloride

    - May be fatal if inhaled, absorbed through the skin or swallowed. Causes eye, skin,

    and respiratory tract irritation. Aspiration hazard if swallowed. Can enter lungs

    and cause damage. Cancer suspect agent. May cause liver and kidney damage.

    May cause central nervous system effects. This is a CFC substance which destroys

    ozone in the upper atmosphere. Destruction of the ozone layer can lead to

    increased ultraviolet radiation which, with excess exposure to sunlight, can lead to

    an increase in skin cancer and eye cataracts. Marine pollutant.

    - Wear chemical safety goggles, protective gloves, and clothing to prevent exposure.

    Bromine

    - Strong oxidizer. Contact with other material may cause a fire. Corrosive. Causes

    eye and skin burns. May cause severe respiratory tract irritation with possible

    burns. May cause severe digestive tract irritation with possible burns.

    Lachrymator (substance which increases the flow of tears). May cause central

    nervous system effects. May cause cardiac disturbances. May cause liver and

    kidney damage.

    - Wear chemical goggles and face shield, protective gloves, and clothing to prevent

    exposure.

    NaOH

    - Mucous membrane irritant. Skin: severe irritation, sensitization, dermatitis &

    burns. Eyes: irritation,conjunctivitis& burns. Ingestion: damage to mucous

    membranes or tissues.

    - Wear protective gloves, and clothing to prevent exposure.

    HCl solution

    - Corrosive to skin, eyes, nose mucous membranes, respiratory & gastrointestinal

    tract. Inhalation:respiratory tract irritation/infection. Severe & fatal

    gastrointestinal burns w/necrosis. Severe burns to eyes & blindness. Changes in

    pulmonary function, chronic bronchitis,dermatitis, tooth erosion, & conjunctivitis.

    - Wear splash chemical goggles, protective gloves, and clothing to prevent

    exposure.

    Soap

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    - May cause eye and skin irritation. May cause respiratory and digestive tract

    irritation. Good laboratory procedures are recommended when handling this

    compound. This is expected to be a low hazard for usual industrial handling.

    - Wear appropriate protective clothing to prevent skin exposure.

    Calcium chloride

    - May cause severe eye, skin and respiratory tract irritation with possible burns.

    May be harmful if swallowed. May cause cardiac disturbances. Hygroscopic

    (absorbs moisture from the air).

    - Wear splash chemical goggles, protective gloves, and clothing to to minimize

    contact with skin.

    Magnesium chloride

    - May cause eye irritation.

    - Wear splash chemical goggles, protective gloves, and clothing to to minimize

    contact with skin.

    Iron (III) chloride

    - Harmful if swallowed, inhaled or absorbed through skin.

    - Wear splash chemical goggles, protective gloves, and clothing to prevent exposure.

    Ammonium molybdate

    - Causes eye and skin burns. Strong oxidizer. Contact with other material may

    cause a fire. Causes severe digestive and respiratory tract burns.

    - Wear protective goggles, protective gloves, and clothing to prevent exposure.

    Nitric acid

    - May be fatal if inhaled. Causes severe eye and skin burns. Causes severe

    respiratory and digestive tract burns. Strong oxidizer. Contact with other material

    may cause a fire. Acute pulmonary edema or chronic obstructive lung disease may

    occur from inhalation of the vapors of nitric acid. Corrosive to metal.

    - Wear chemical splash goggles and face shield, butyl rubber gloves, and clothing

    to prevent skin exposure

    Mineral oil

    - May cause eye and skin irritation. May cause respiratory and digestive tract

    irritation.

    - Wear appropriate protective eyeglasses, protective gloves, protective clothing to

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    prevent skin exposure.

    VI. QUESTIONS AND PROBLEMS

    1. From all of the solvents that have been experimented, which is the best solvent to

    vanish oil stain or fat from clothes?

    2. How many gram of bromine needed to react completely with 1 mol triglyceride that

    contains only oleic acid?

    3. Why do we use saturated concentration sodium chloride solution to precipitate soap?

    4. What reaction will happen when calcium ion is added to the soap solution?

    5. Do metal salt solution from the carboxylic acid and sulphate alkyl look the same as the

    metal salt solution from CO32- and SO4

    2-

    6. Arsenate Ion, AsO43- will react with ammonium molybdate, same with phosphate.

    Explain why and what ion will be produced?

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    VII. REPORT FORMAT

    Name ______________ Date ______________

    Partner ______________ Lab. Assistant ______________

    REPORT SHEET

    The Solubility of Cotton Seed Oil

    No. Sample Solubility

    Shake Add Solvent Shake

    1 Water

    2 Ethanol

    3 Hexane

    4 Carbon tetrachloride

    Unsaturated Triglyceride

    No Sample Amount of Drops Need

    1 Cottonseed Oil

    2 Crisco

    Soap

    Alkaline Characteristic

    No Sample Colour of Litmus Paper

    1 Soap

    2 Commercial soap

    3 Detergent

    Emulsion Characteristic

    No Sample Characteristic

    1 Mineral Oil

    2 Soap

    3 Commercial Soap

    The Effect of Metal Salt

    No. Sample Solution

    Calcium chloride Magnesium chloride Iron (III) chloride

    1 Soap

    2 Commercial soap

    3 Detergent

    Experiment 9

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    EXTRACTION AND IDENTIFICATION OF FATTY ACIDS FROM CORN OIL

    I. OBJECTIVES

    To extract fatty acids from neutral fats.

    To convert them to their methyl esters.

    To identify them by thin-layer chromatography.

    II. INTRODUCTION

    Fats are esters of glycerol and fatty acids. Liquid fats are often called oils. Whether a

    fat is solid or liquid depends on the nature of the fatty acids. Solid animal fats contain mostly

    saturated fatty acids, while vegetable oils contain high amounts of unsaturated fatty acids. To

    avoid arteriosclerosis, hardening of the arteries, diets which are low in saturated fatty acids as

    well as in cholesterol are recommended.

    Note that even solid fats contain some unsaturated fatty acids, and oils contain

    saturated fatty acids as well. Besides the degree of unsaturation, the length of the fatty acid

    chain also influences whether a fat is solid or liquid. Short chain fatty acids, such as found in

    coconut oil, convey liquid consistency in spite of the low unsaturated fatty acid content. Two

    of the unsaturated fatty acids, linoleic and linolenic acids, are essential fatty acids because the

    body cannot synthesize them from precursors; they must be included in the diet.

    The four unsaturated fatty acids most frequently found in vegetable oils are:

    All the C=C double bonds in the unsaturated fatty acids are cis double bonds, which interrupt

    the regular packing of the aliphatic chains, and thereby convey a liquid consistency at room

    temperature. This physical property of the unsaturated fatty acid is carried over to the

    physical properties of triglycerides (oils).

    In order to extract and isolate fatty acids from corn oil, first, the ester linkages must be

    broken. This is achieved in the saponification reaction in which a triglyceride is converted to

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    glycerol and the potassium salt of its fatty acids:

    In order to separate the potassium salts of fatty acids from glycerol, the products of

    the saponification mixture must be acidified. Subsequently, the fatty acids can be extracted

    by petroleum ether. To identify the fatty acids that were isolated, they must be converted to

    their respective methyl ester by a perchloric acid catalyzed reaction:

    The methyl esters of fatty acids can be separated by thin-layer chromatography (TLC).

    They can be identified by comparison of their rate of migration (Rf values) to the Rf values of

    authentic samples of methyl esters of different fatty acids (Fig. 4.1).

    Figure 4.1 TLC Chromatogram

    Rf = distance travelled by fatty acid/distance travelled by the solvent front.

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    III. EQUIPMENT & CHEMICALS

    III.1. Equipment

    1. Aluminum foil

    2. Polyethylene gloves

    3. 15 x 6.5 cm silica gel TLC plate

    4. Capillary tubes open on both ends

    5. Heat lamp

    6. 18.Water bath

    7. Ruler

    8. Drying oven, 110 OC

    III.2. Chemicals

    1. Corn oil

    2. Methyl palmitate

    3. Methyl oleate

    4. Methyl linoleate

    5. Petroleum ether (b. p. 3060 OC)

    6. 0.5 M KOH in ethanol

    7. Concentrated HCl

    8. Anhydrous Na2SO4

    9. Methanol: perchloric acid mixture (95:5)

    10. Hexane: diethyl ether mixture (4:1)

    11. Iodine crystals, I2

    IV. PROCEDURES

    IV.1. Extraction of Fatty Acids

    1. Weigh a 50-mL Erlenmeyer flask and record the weight on your Report Sheet (1).

    2. Add 2 mL of corn oil and weigh it again. Record the weight on your Report Sheet (2).

    3. Add 5 mL of 0.5 M KOH in ethanol to the Erlenmeyer flask. Stopper it. Place the

    flask in a water bath at 55 OC for 20 min.

    4. When the saponification is completed, add 2.5 mL of the concentrated HCl. Mix it by

    swirling the Erlenmeyer flask. Transfer the contents into a 50-mL separatory funnel.

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    Add 5 mL of petroleum ether. Mix it thoroughly. Drain the lower aqueous layer into a

    flask and the upper petroleum ether layer into a glass-stoppered test tube. Repeat the

    process by adding back the aqueous layer into the separatory funnel and extracting it

    with another portion of 5 mL of petroleum ether. Combine the extracts.

    IV.2. Preparation of Methyl Esters

    1. Place a plug of glass wool (the size of a pea) into the upper stem of a funnel, fitting it

    loosely. Add 10 g of anhydrous Na2SO4. Rinse the salt on to the glass wool with 5 mL

    of petroleum ether; discard the wash. Pour the combined petroleum ether extracts into

    the funnel and collect the filtrate in an evaporating dish. Add another portion (2 mL)

    ofpetroleum ether to the funnel and collect this wash, also in the evaporating dish.

    2. Evaporate the petroleum ether under the hood by placing the evaporating dish on a

    water bath at 60 OC. (Alternatively, if dry N2 gas is available, the evaporation could be

    achieved by bubbling nitrogen through the extract. This also must be done under the

    hood.)

    3. When dry, add 10 mL of the CH3OH:HClO4mixture (95:5). Place the evaporating dish

    in the water bath at 55 OC for 10 min.

    IV.3. Identification of Fatty Acids

    1. Transfer the methyl esters prepared above into a separatory funnel. Extract twice with

    5 mL of petroleum ether. Combine the extracts.

    2. Prepare another funnel with anhydrous Na2SO4 on top of the gla