1b. looking at water & its contaminants

1B. Looking at Water & 1B. Looking at Water & Its ContaminantsIts Contaminants

Learning more about the chemistry of water and how substances interact with water

Do Now: (day 1)

Read Article on pg. 25 and write a paragraph summary addressing: water tests that were performed Concerns Other important information

Do Now (cont.)

Concerns Dissolved oxygen (DO) levels – will test Microorganisms – none present Dissolved matter – must consider amounts

& effect of temperature on solubility – will test

Suspended particles – will test Other Information

No illness – water conservation tips – more water trucked in – 3 day crisis expected

Now what?Now what?

Water experts agree that the fish kill was caused by something either dissolved or suspended in the Snake River.

How can you determine the exact cause? Knowing properties of water & properties

of substances that may be found in it will help.

Knowing language of chemistry will help you communicate your findings.

4

Objectives

SWBAT compare and contrast surface tension between water and alcohol

SWBAT define matter and discuss the physical properties of water.

SWBAT calculate density

1B.1 PHYSICAL PROPERTIES 1B.1 PHYSICAL PROPERTIES

OF WATEROF WATER

6

Mini- group activity- WKST U1B2

PREDICTION: How many drops of water can a penny

hold without spilling over?

Surface Tension

Water is very common… on EarthWater is very common… on Earth

70% of Earth’s surface covered by oceans – average depth of 3 km (2 mi)

Unmatched by any planet or moon in our solar system

9

Matter

MATTER:MATTER: IS ANYTHING THAT HAS MASS IS ANYTHING THAT HAS MASS & OCCUPIES SPACE.& OCCUPIES SPACE.

WATERWATER IS MATTER. IS MATTER.

Let’s think about…

What states of matter can be observed in this winter scene?

Water has Physical PropertiesWater has Physical Properties

Matter can be distinguished by its properties.

Physical properties are those can be observed and measured without changing the chemical makeup of the substance

Ex.- color, odor, density, melting point, boiling point, freezing point.

12

Water has Physical PropertiesWater has Physical Properties

Density – Water’s density is 1.00 g/cm3 or 1.00 g/mL at 25oC – varies by temperature Ex. Mini-lab

Freezing Point – 0oC at normal atmospheric conditions

Any others?

13

Do Now (day 2)

What physical property of water explains the “sheeting action” under the swimmers right arm?

Objectives

SWBAT identify physical properties of substances

SWBAT differentiate between mixtures and substances and heterogeneous and homogenous mixtures

SWBAT create a concept chart of all types of solutions

Unit 1B.2 p2

Think-Pair-Share WKST

““Pure” WaterPure” Water

“Pure” water is water with absolutely nothing else dissolved or suspended in it

Properties of pure waterClearColorlessOdorlessTasteless

17

Substances Dissolve in WaterSubstances Dissolve in Water

Aqueous solutions – water based solutions SOLUTE- substance that is being

dissolved SOLVENT- substance that dissolves

the solute (usually water, in aqueous solutions it is water)

18

Substances Dissolve in WaterSubstances Dissolve in Water

19

Sample Solute Solvent

Salt Water

Coffee

lemonade

1B.3 MIXTURES & SOLUTIONS1B.3 MIXTURES & SOLUTIONS

20

Matter is divided into a mixture or a substance

Mixture: two or more substances coming together but

keeping their individual properties “Foul Water” was a mixture of water, used

coffee grinds, oil, garlic powder, salt

Substance: Definite composition, not physically able to

separate

Types of Mixtures

Homogeneous Mixture: Composition is the same or uniform

throughout

Heterogeneous Mixture: Composition is not the same or uniform

throughout.

2 Types of Heterogeneous Mixtures2 Types of Heterogeneous Mixtures

Suspension – heterogeneous mixture containing large, solid particles that can settle out or be separated by filtration

Colloid – heterogeneous mixture containing particles too small to settle out – cloudy – Tyndall effect

24

SolutionsSolutions

All solutions are homogeneous mixtures

A solute dissolves in a solvent to make a solution

Solutions are clear but not necessarily colorless

A conductivity test indicates the presence of dissolved charged particles

25

Types of Substances

Elements: One type of atom

Compounds: Two or more types of atoms chemically

bonded together

Do Now

What are the two major types of mixtures?

What is the difference between a suspension and a colloidal dispersion?

Objectives

SWBAT review the differences between types of mixtures.

SWBAT create a concept chart of substances and mixtures and provide examples of each.

SWBAT differentiate between symbol, element, compound, and molecule.

Create a concept chart and write an example of each category.

1B.4 PARTICULATE VIEW OF 1B.4 PARTICULATE VIEW OF

MATTERMATTER

30

Particulate LevelParticulate Level

To understand the macroscopic (large scale & readily observed) properties of water, you have to understand water’s behavior at the particulate level – the level of small particles – the level of atoms and molecules

31

SubstancesSubstances

Atoms – “building blocks of matter”

Elements – made of one kind of atom

Represented by symbols (H, O, Ne) & sometimes formulas (H2, O2)

Molecules – made of atoms joined together – atoms can be the same or different

Compounds – made of different elements combined together

Represented by formulas (H2O, KCl)

32

33

Refer to your te

xt

and/or handout fo

r

details.

MODELS:MODELS:REPRESENTATIONS OF ATOMS REPRESENTATIONS OF ATOMS & MOLECULES& MOLECULES

These pictures are one kind of model (space filling model).

34

Models of WaterModels of Water

“Seeing and Imagining Water” Visit the online site for 1B

http://www.whfreeman.com/chemcomstudent/index2.html

35

1B.5 PICTURES IN THE MIND1B.5 PICTURES IN THE MIND

Modeling Matter

36

Drawing ModelsDrawing Models

Sample Problem: Draw a model of two gaseous compounds in a homogeneous mixture.

What do you need to know to draw your model?What is a homogeneous mixture?What might a gaseous compound look like?How many compounds are in this mixture?

There is more than one drawing possible.

37

Do Now Describe the picture:

1. What type of mixture is this? 2. How many compounds? 3. What state of matter?

Objectives

SWBAT classify pictures as homogeneous, heterogeneous, gas, solid, or liquid.

SWBAT identity the number of different compounds in a substance or mixture

SWBAT draw different mixtures and answer questions related to those pictures

Drawing ModelsDrawing Models

Which of the following drawings best represents a homogeneous mixtures of two gaseous compounds?

40

Drawing ModelsDrawing Models

The best answer is “b.”

41

• 2 types of molecules are uniformly mixed• Atoms are colored to represent different elements

• Not homogeneous

• 3 different compounds, not 2

“b” & “c” are space-filling models. “a” is a ball-and-stick model. Both are acceptable.

Drawing ModelsDrawing Models

Finish the 7 questions for the B.5 Pictures in the Mind modeling matter activity on pp. 33-34.

42

Homework

Pg. 50 #1-4, 6-8, 10

Do Now

Name 4 elements

Where can you find each one?

Objectives

SWBAT understand the requirements for the mole day project

SWBAT determine numbers of atoms in a formula

SWBAT identify elements on the periodic table and understand how to write their symbols

SWBAT research and create a poster about a particular element

1B.6 SYMBOLS, FORMULAS, & 1B.6 SYMBOLS, FORMULAS, &

EQUATIONSEQUATIONS

46

Symbols, Formulas, & EquationsSymbols, Formulas, & Equations

The international language of chemistry includes symbols, formulas, & equations.Symbols are like letters.Formulas are like words.Equations are like sentences.

47

The “letters”The “letters”Symbols – Elements Symbols – Elements Elements are

organized on the Periodic Table of Elements

Each element is represented by a symbol Capital letter Capital letter &

lower case letter Find some of these

symbols on the Periodic Table.

48

The Periodic Table of Elements contains much more useful information than just symbols.

You will be learning more about this table throughout this course.

49

People use aluminum to make a variety of products, including foil, cans, & lightweight construction materials.

50

Silicon has properties that lie between those of metals and nonmetals. It is classified as a metalloid. One of its primary uses is in electronic devices.

51

Sulfur is a nonmetal used in products such as fungicides and rubber of automobile tires.

The “words”The “words”FormulasFormulas

Formulas represent specific chemical substances.

Formulas are made of symbols.

Formulas may include subscripts.

A subscript refers back to the symbol immediately before it. A “1” is “understood” & not written.

52

Examples

CO 1 carbon & 1 oxygen

CO2

1 carbon & 2 oxygens NH3

1 nitrogen & 3 hydrogens H2O

2 hydrogens & 1 oxygen H2SO4

2 hydrogens, 1 sulfur, & 4 oxygens

Diatomic ElementsDiatomic Elements

Most elements exist as individual atoms and are represented with symbols.

Some elements exist as 2 bonded atoms of the same element.

For example, hydrogen is a diatomic gas, so is always written as H2 when it is an uncombined element.

54

7 “GEN-U-INE DIATOMICS”

The names of all diatomic elements end in GEN or INE, and U should remember them!

55

The 7 diatomic elements are all gases, but not all gases are diatomic.

Where are the 7 diatomic elements found on the Periodic Table?

The “sentences”The “sentences”EquationsEquations

Equations give the details of chemical reactions

Chemical reactions involve the breaking & making of chemical bonds, causing atoms to be rearranged into new substances.

The new substances have different properties from those of the original materials.

56

The “sentences”The “sentences”EquationsEquations The original substances (reactants) are

written first. Then, an arrow points to the new substances that are made (products).

reactants productshydrogen + oxygen water

2H2 + O2 2H2O Note that this equation is “balanced.”

The total number for each kind of atom is the same for both reactants & products. 57

Do Now

During yesterday’s class, we used a metaphor in chemistry. Tell me what the following stood for and provide an example of each.

Letters= Ex. Words= Ex. Sentences= Ex.

Objectives

SWBAT define protons, neutrons, and electrons and determine the number of them in a given element.

SWBAT draw out Lewis Diagrams of different atoms

Determining Electron, Proton, and Neutron Number

Parts of the Atom Proton-

In nucleus, positive charge and a mass of 1

Neutron- In nucleus, neutral charge and a mass

of 1 Electron-

Outside nucleus, negative charge and no mass

+

-

Complete the chart

Part of Atom

Charge Mass

Proton

Neutron

Electron

So… if this is an atom…

What makes atoms different? How is carbon different from

oxygen? Different numbers of protons

Oxygen

O15.99

8

(number of protons)

(number of protons and neutrons)

(Oxygen)

Atomic

Number

Atomic MassAtomic Mass

Element

Symbol

Practice Problems

N7

9.01

4

Ne20

C12.02

Complete the missing information and include the number of protons, neutrons, and electrons.

Worksheet

Do Now

Draw out the atom, F (atomic #_____)

Objectives

SWBAT draw out Lewis Diagrams of different atoms

SWBAT identify ions as cations and anions and be able to determine the formula for ions and be able to name them.

SWBAT work in groups to answer questions as a conclusion to activity

1B.7 SYMBOLS, FORMULAS, & 1B.7 SYMBOLS, FORMULAS, &

EQUATIONSEQUATIONS

Developing Skills, p. 36 #1-3

69

Lewis Dot Structure

Drawing representing the outer most (valence) electrons

EX.

Worksheet

1B.8 THE ELECTRICAL 1B.8 THE ELECTRICAL

NATURE OF MATTERNATURE OF MATTER

72

Rubbing a balloon against your hair results in static electricity.

Clothes taken out of the drier often show static cling.

The shock that you sometimes receive after you walk across a rug & touch a doorknob is another example of matter’s electrical nature.

What causes these phenomena?

73

Static cling is best seen when the humidity is low.

Attraction & RepulsionAttraction & Repulsion

The electrical properties of matter can be summarized as follows:

What are these positive and negative particles?

74

Subatomic ParticlesSubatomic Particles

Every neutral (uncharged) atoms contains an equal number of positively charged protons (+) and negatively charged (-) electrons.# of (+) protons = # of (-) electrons

Positive-Negative attractions between the protons in one atoms the electrons in another atom hold atoms together in bonds.

Most atoms also contain neutral particles having no charge (0) called neutrons. 75

Do Now

Draw the Lewis Dot Diagrams for the following Atoms:

Ca

Li

F

Objectives

SWBAT identify cations and anions SWBAT calculate the number of

protons, neutrons, and electrons in different ions

SWBAT name and determine the formula for several ions

1B.9 IONS & IONIC 1B.9 IONS & IONIC

COMPOUNDSCOMPOUNDS

78

Ions and Ionic CompoundsIons and Ionic Compounds

Recall: Molecules make up one kind of compound.

Ions make up another kind of compound.

Ions are electrically charged atoms (or groups of atoms).

Ions are formed when neutral atoms gain or lose electrons.

79

IonsIons

Ions are electrically charged atoms (or groups of atoms).

Ions are formed when neutral atoms gain or lose electrons.

80

IonsIons

Recall: What charge do electrons carry?Negative

When atoms gain negative electrons, they form negative ions.

When atoms lose negative electrons, they form positive ions.

81

IonsIons

For example, sodium (Na) is # 11 on the Periodic Table.

It has 11 (+) protons and 11 (-) electrons. If it lost 1 (-) electron, it would have 11 (+)

protons and 10 (-) electrons. It has one more proton than electrons, so it

has a charge of -1. The symbol for a sodium ion is Na1+ or just

Na+. (The 1 is understood.)

82

IonsIons

For another example, chlorine (Cl) is # 17 on the Periodic Table.

It has 17 (+) protons and 17 (-) electrons. If it gained 1 (-) electron, it would have 17

(+) protons and 18 (-) electrons. It has one less proton than electrons, so it

has a charge of +1. The symbol for a chloride ion is Cl1- or just

Cl-. (The 1 is understood.)

83

Do Now

List the number of protons, electrons, and neutrons in each ion O2-

H+

F3-

Do any of these atoms have complete valence shells?

Objectives

SWBAT determine the formulas for ionic compounds

SWBAT name different ionic compounds

Ionic CompoundsIonic Compounds

Oppositely charged ions connect together to form ionic compounds.

For example, sodium ions (Na+) connect to chloride ions (Cl-) to make sodium chloride (NaCl), or table salt.

86

Sodium chloride consists of an equal number of positive and negative ions arranged in a 3-dimensional network called a crystal.

87

A scanning electron micrograph shows the cubic structure of NaCl crystals.

A space-filling model of NaCl provides information about how the individual sodium ions & chloride ions are arranged within the salt crystal.

88

What else does this model suggest about the sodium and chloride ions or sodium chloride?

If an ionic compound dissolves in water, the individual ions would separate from each other and spread out throughout the water.

To show that they were now in an aqueous solution, an (aq) would be added after the symbols for the ions.

Na+(aq) Cl- (aq)

89

More about IonsMore about Ions

Cation – positive ion

Anion – negative ion

Monoatomic ions (or monatomic)

Polyatomic ions

Na+, Cl-, Mg2+, O2-, Al3+, N3-

NH4+, CO3

2-, SO42-,

PO43-

90

Common IonsCommon Ions

See text p. 40 for a list of common ions.

91

Formulas for Ionic CompoundsFormulas for Ionic Compounds

2 Rules for Writing Formulas for Ionic Compounds

1. Cation first, then anion

2. Correct formula will be neutral, with the fewest number of each ion needed to make the total electrical charge zero

No charges are shown in the formula.

92

Practice Problems

NaCl One Na1+ and one Cl1- cancel each other out.

+1 + -1 = 0

CaCl2

One Ca2+ needs two of the Cl1- to cancel it out. +2 + -1 + -1 = 0

Note: Negative monoatomic ions change their ending to “ide.”Examples above are sodium chloride and calcium chloride.

Formulas Containing Formulas Containing Polyatomic IonsPolyatomic Ions

Formulas for compounds containing polyatomic ions follow the same rules

If a subscript is needed, it follows the entire polyatomic ion, which is enclosed in parentheses

For example, the calcium ion has a +2 charge, and the nitrate ion has a -1 charge

94

Formulas Containing Formulas Containing Polyatomic IonsPolyatomic Ions

For example, the calcium ion has a +2 charge (Ca2+), and the nitrate ion has a -1 charge (NO3

1+). Two nitrate ions are needed to balance

out the charge on one calcium ion. The formula for calcium nitrate is:

Ca(NO3)2. No charges are shown in the formula.

Polyatomic ions do not change their endings.

95

Naming Ionic Compounds

1. Name the cation, then the anion 2. Have the last few letters changed

to –ide (monoatomic ions only)

Ex. KF, potassium fluoride

Ex. Ca(NO3)2, calcium nitrate

Do Now

Write the formula and name the following ionic compounds

1. Ca2+ Br-

2. PO43- Ag+

3. CO32- NH4

+

4. Al3+ NO3-

What does the word “ionic” mean?

Objectives

SWBAT determine the formulas for several polyatomic and monoatomic compounds

SWBAT explain what a mole is and present their projects

SWBAT read fun facts about the mole

1B.10 IONIC COMPOUNDS1B.10 IONIC COMPOUNDS

Developing Skills, p. 41

99

IB.11 WATER TESTINGIB.11 WATER TESTING

Investigating Matter, pp. 42-45

100

Do Now

Explain what charge the following items typically carry and WHY!

Lithium Chlorine Calcium

Figuring out Charges

Do Now

1. Draw the Lewis Dot diagram for Li+.

2. Draw a picture of a heterogeneous mixture of elements X and B.

Objectives

1. SWBAT start to review for the test by going over the answers review questions.

2. SWBAT read and think critically about the Riverwood Fish Kill.

3. SWBAT create 2 possible hypothesis about the Riverwood fish kill.

Take out questions:

Pg. 51 #15-24

1B.12 PURE AND IMPURE 1B.12 PURE AND IMPURE

WATERWATER

106

Pure vs. Clean WaterPure vs. Clean Water

In the U.S., we all have access to abundant, low cost, clean, but not pure water

Even if the cost was not prohibitive, it would be impossible to have 100% pure water.

Atmospheric gases (e.g., O2, N2, CO2) will always dissolve in the water to some extent.

107

IB.13 THE RIVERWOOD IB.13 THE RIVERWOOD

WATER MYSTERYWATER MYSTERY

Making Decisions, p. 46

108

1B.14 WHAT ARE THE 1B.14 WHAT ARE THE

POSSIBILITIES?POSSIBILITIES?

109

HOW DO YOU NARROW DOWN HOW DO YOU NARROW DOWN THE DATA TO GET THE THE DATA TO GET THE ANSWER?ANSWER?

The cause of the fish kill may be related to something suspended in or dissolved in the water. What might it be?

110

Chemistry at WorkChemistry at Work

To learn about careers that require knowledge about what you are learning about in class right now, read text pp. 48-49, Environmental Cleanup: It’s a Dirty Job… But That’s the Point

111