IB DIPLOMA CHEMISTRY LAB REPORTPRACTICAL 7

INTRODUCTION

Most of the physical and chemical properties of a substance can be related to the type of bonding present in that substance. Substances that are ionically bonded contained positive and negative ions. Substances that are covalently bonded contains molecules; if the molecules contain atoms of different sorts, they may be polar due to the equal sharing electrons between the different atoms. The amount of polarity in a molecule, determined by the shape of the molecule and the relative electronegativities of the atoms in it, has a great effect on the properties of the substance.

PURPOSE AND OBJECTIVE:

1. To observe the effect of a charged rod on liquid jets.2. To test the miscibility of liquids.3. To test the solubility of iodine in different liquids.4. To test the solubility of graphite in liquids.5. To test the solubility of calcium chloride in liquids.6. To test the volatility of iodine, graphite and calcium chloride.7. To test the conductivity of chemical solutions.

Experiment I: The Effect of a charged rod on liquid jets .

DATA COLLECTION:

Types of liquid Observation Inference1. Water Draws near to the polythene rod Attract to the polythene rod2. Hexane No changes to the jet of hexane No attraction happened3. Ethanol Draws near to the polythene rod Attract to the polythene rod

DATA PROCESSING:

1. When the rod is rubbed by the fur, the rod will gain electrical charges.

2. When the rod is held near the water and ethanol jets, the liquid jets are attracted to the rod. This is because in water and ethanol there are polar elements. This polar element is attracted to the charged rod.

3. When the same rod is put near the jet of hexane, there is no change happen to the jet of hexane because hexane is non-polar liquid means do not carry any charge.

Experiment II: Miscibility of Liquids

DATA COLLECTION:

Types of liquid Observation Inference1. Water and Ethanol Mixed together The liquids are miscible2. Water and Hexane 2 separated colourless

layers are formedThe liquids are immiscible

3. Hexane and Ethanol Mixed together The liquids are miscible

DATA PROCESSING:

1. Water is a polar solvent which dissolves polar solutions. Ethanol has hydroxyl groups which are polar. The polar elements will create ionic bonds between each other making them miscible.

2. Hexane does not have any polar element therefore no bond will be created between water and hexane, so hexane cannot be dissolved in water.

3. Hexane is a non-polar element while ethanol has a non-polar chain in the structure, so there are covalent bonds between the two elements hence they are miscible with each other.

Experiment III: Solubility of iodine in different liquids .

DATA COLLECTION:

Types of Iodine solution Observation Inference1. Iodine in distilled water Colourless solution Iodine is slightly soluble in

water2. Iodine in ethanol Dark orange solution Iodine is very soluble in

ethanol3. Iodine in Hexane Purple solution Iodine is slightly not soluble

in hexane

DATA PROCESSING:

1. Iodine crystal is not soluble in water as in its solid form it is not polar molecules but is joined together covalently. The yellow solution is the result of iodine in the form of ions which is not pure solid iodine molecule.

2. Iodine crystal is covalent molecules which dissolve in the covalent part of ethanol. This is due to the covalent bond between iodine crystal and ethanol.

3. Iodine crystal is covalent molecules which dissolve in hexane as hexane is a covalent substance. The bond between the two elements is covalent bond.

Experiment IV: Solubility of graphite in liquids

DATA COLLECTION:

Types of graphite solution Observation Inference1. Graphite in distilled

waterMany dark tiny particles present

Graphite is not soluble in water

2. Graphite in Ethanol Many dark tiny particles present

Graphite is not soluble in ethanol

3. Graphite in Hexane Many dark tiny particles present

Graphite is not soluble in hexane

DATA PROCESSING:

1. Graphite is consists of molecules which bonded with covalent bonding. It is a giant covalent compound which is very stable that does not dissolve in an ionic-bonded solution or a covalently-bonded solution. Only if there is high energy such as the factor of high heat will break the strong covalent bond in graphite to dissolve in a covalent-bonded solution.

Experiment V: Solubility of calcium chloride, CaCl in liquids

DATA COLLECTION:

Types of CaCl solution Observation Inference1. CaCl and distilled water White precipitate present CaCl is very soluble in

water2. CaCl in Ethanol White precipitate present CaCl is slightly soluble in

ethanol3. CaCl in Hexane 2 separated colorless

solution formedCaCl is not soluble in hexane

DATA PROCESSING:

1. Calcium chloride is an ionic compound which ionized in water to form calcium ions and chloride ions which will form ionic bonds with water.

2. The hydroxyl group in ethanol will form ionic bonds with calcium ions and chloride ions. This will result in the solubility of calcium chloride in ethanol.

Experiment VI: Volatility of Iodine, Graphite, and Calcium chloride .

DATA COLLECTION:

Types of Solids Observation Inference1. Iodine Dark purple gas pouted out Iodine crystal quickly

sublimes into purple vapour2. Graphite No changed Graphite does not sublime.3. Calcium chloride Colourless gas pouted out

after quite a timeCalcium chloride is sublime lately after quite a time

DATA PROCESSING:

1. Iodine crystal quickly sublimes into purple vapour because iodine molecules are attracted to one another by weak van der Waals’ force. So only a small quantity of energy is required to break the forces.

2. Graphite did not show any reaction because it molecular bonding are in the form of strong carbon bond. So it is hard to break the bond with small amount of heat hence result in subliming it directly.

3. Calcium chloride is actually bounded with ionic bond that has high evaporated point. Therefore enough heat provided can break down the ionic bond at an interval time.

Experiment VII: Conductivity of Iodine, Graphite, and calcium chloride in different solution.

DATA COLLECTION:

Solvent Ammeter Readings, A ±0.2Substances Water Hexane Ethanol1. Iodine 0.2 0.0 0.02. Graphite 0.0 0.0 0.03. Calcium

chlorideMore than 100 8.0 28.

DATA PROCESSING:

1. Iodine cannot conduct electricity because it does not ionize in any of the solvents. It is because only the present of the freely moving electrons can carry the electricity.

2. Calcium chloride conducts electricity because it ionizes in all of the solvents. Calcium chloride ionizes completely in water and result the biggest current compared to other solution.

3. Less current is generated in solution of calcium chloride and ethanol because ethanol is semi polar. Least current is generated from hexane because hexane is non-polar.

Experiment VIII: The colour of iodine in different solvent

DATA COLLECTION:

Solvents / Mixture Colour Observation1. Hexane Purple2. Ethanol Dark orange3. Ethoxyethane (ether) Pale Yellow4. Ethyl Ethanoate Dark brown5. Trichloromethane Purple6. A drop of ethanol to a mixture of iodine + hexane Colour changes from purple to

dark brown7. A drop of hexane to a mixture of iodine + ethanol The colour remains brown in

colour

DATA PROCESSING:

1. Iodine is non-polar therefore soluble in hexane and trichloromethane because they are also non-polar.

2. Ethanol and ethyl Ethanoate are more polar than hexane. Thus, the solution turns brown which indicates that iodine slightly dissolve in these solvents.

3. Ethoxyethane or ether is more polar than ethanol. Thus, the solution turns pale yellow which indicates that iodine dissolves more in the solvent..

CONCLUSION

1. The polar liquid jet will affected with the charged rod while the non-polar liquid jet cannot be affected.

2. Polar compounds dissolve in polar compounds while non-polar dissolve in non-polar.

3. Graphite unable to dissolve in any of the solvents because held by a strong carbon bond

4. Ionic bond is stronger than covalent bond. But, carbon bond is stronger held than ionic bond.

5. Compounds that can ionize in a solution will conduct electricity.