[duniaSMA] Making Colloid

I. Instrument and Material

Instrument : Chemical glass, burner device, tripod and gauze, tubes, a tube’s rack,

pipette, spatula mortar, and pounder.

Materials : - Distilled water

- Saturated solution of FeCl3

- Sugar and Sulfur Powder

- Cooking oil, white egg, salt, some detergent, lemon water

II. Activity Step

MAKING IRON (III) HYDROXIDE SOL AND SEAWEED GELATINE SOL

Purpose : Making and monitoring how to make Fe(OH)3 sol and gelatine sol

Method : Using by condensation method

1. Making Iron (III) hydroxide sol
1. Put 25 ml of distilled water into a chemical glass and heat it.
2. Add about 20-45 drops of saturated FeCl3 solution then stir slowly while keeping in it heat
3. Stop heating when solution begins to be brown red in colour
4. Observe the change
2. Making Seaweed gelatine sol
1. Put about 2 grams of seaweed gelatine into reaction tube
2. Contains water at half tube
3. Heat the solution then stir it until the gelatine dissolved
4. Cool the tube.

MAKING SULFUR SOL

Purpose : Make colloid with mechanic dispersion way

Method : Using by Dispersion method

3. Making Sulfur sol
1. Crush 1 spoonful of sugar and 1 spoonful of sulfur powder in a mortar by using powder
2. Take half of the sugar-sulfur mixture
3. Add into the mixture 1 spoonful of sugar and crush mixture again
4. Do step above twice
5. Take 1 spoonful of the last crushing product then put it into water
6. Observe the mixture produced
7. Take sugar and sulfur powder which are not yed crushed, then put them into 50 ml of distilled water.
8. Observe the mixture produced and compare it with the mixture of sugar-sulfur which have been crushed

PROVE SHEET

No	Experiment	Observation
1.	Making Fe(OH)3 sol	Happened colloid
2.	Making seaweed gelatine	Change be jelly
3.	Making sulfur sol	Happened colloid

THE PROBLEM

1. What are the phenomena which you can observe in making colloids by using those two methods?

In first method, we can saw the solution of Fe (OH)3 mixed with water and happened colloid. We call Iron (III) hydroxide sol and we can saw the solution of seaweed gelatin mixed with water change be jelly. We called Seaweed Gelatin Sol.

In second method, we can saw the sugar-sulfur mixture after crush and mix with water, happened colloid. But sugar-sulfur mixture which are not yet crushed and mix with water, didn’t happen colloid, the sulfur fly and swing in water surface.

2. What is the function of sugar in experiment making sulfur sol?

Sugar has function as a substance to mix sulphur with water

3. How to purity those colloid above?

Solution	Color	Observation
		Initial	After mixture	Cooling
Fe(OH)3	Brown	Brown	Brown red	Brown red
Seaweed	White	Turbid	Turbid	Jelly
Sulfur sol	Yellow	Turbid	Turbid	Turbid

4. Write down the reaction of making Fe(OH)3 sol?

FeCl2 + H2O Fe(OH)3 + HCl

CONCLUTION

INTRODUCE COLLOID SYSTEM

4. Making Oil Emulsion in Water
1. Prepare 4 tubes and put them on rack, pour 3 ml water and 3 ml cooking oil in each tube
2. Put 1 spoonful of salt, egg white, lemon water and detergent into each tube
3. Shake all tubes and let it for a while
4. Observe the result
5. Write down your observation result

PROBLEM

1. What happens when you mix water and oil?

Water and oil did not mix.

2. What happens when you put detergent into water and oil mixture?

Water and oil can mixed because the detergent is suspension system so can make the water and oil mix.

3. What substance that can function as emulsifier in experiment?

Detergent have function as emulsifier in experiment

4. What substance that cannot function as emulsifier in the experiment above?

Egg and salt cannot function as emulsifier in that experiment

5. What is your conclusion from the experiment above?

Detergent have function s-emulgator –substance which can make stabile colloid—

and the egg and salt cannot function as emulsifier in that experiment