Laporan Praktikum Pembuatan Koloid (MAKING COLLOIDS)

I.            TOPIC          : Making colloids by condensation method and dispersion method.

II.          OBJECTIVE        

1.    To make colloids by condensation method.

2.    To make colloids by dispersion method.

III.         BASIC THEORY

Colloid is a heterogeneous mixture between two substances or more which is dispersion phase spread evenly in its dispersion medium. Colloid particles have size about 1-100 nm. Colloid is a mixture that its size between suspension and solution. Colloid seems like homogeneous substance but actually it is heterogeneous substance.

The characteristic of colloid are:

a.  Tyndall effect

Colloid particles disseminate light it called Tyndall effect.

b. Brownian movement

Brownian movement is colloid particles movement in zigzag line.

c.  Adsorption

Adsorption is charge absorption by colloid particles surface.

d.  Coagulation

Coagulation is coagulating process from colloid particles so stability is decrease.

e.  Colloid protector

Colloid protector is adding colloid into other colloid so it will stable.

f.   Lyophilize colloid

Lyophilize colloid is colloid that its dispersion phase liked to draw its dispersion medium.

g.  Lyophob colloid

Lyophob colloid is colloid that its dispersion phase doesn’t like to draw its dispersion medium.

      Making colloid can be made by two methods are dispersion and condensation. Dispersion method can be made by three ways are mechanic, peptisasion, and Bredig arc. Condensation can be made by four ways are hydrolyze, redoks, solvent replacement, and mix watery solutions. Mechanic way is did by grind substance so it become colloid. Peptisasion is knapping big particles by adding knapping substance. Bredig arc is a tool that used to make metal colloid. Hydrolyze is making colloid in water. Redoks is making colloid that is engage oxidation number changing.

IV.         TOOLS AND MATERIALS

a.    Tools:

1.    Beaker glass

2.    Burning cup

3.    Safety match

4.    Flashlight

5.    Spatula

6.    Mortar porcelain

7.    Pestle porcelain

8.    Reaction tube

9.    Bunsen

b.   Materials:

1.    7 ml calcium acetate

2.    40 ml alcohol 95%

3.    3 ml AgNO₃ solution 0,1 M

4.    5 ml HCl 0,1 M

5.    Sugar

6.    Sulfur powder

7.    Water

8.    Jelly powder

9.    1 ml kerosene

10. Detergent

V.           WORK STEP

A.    Make colloids with condensation method:

1.    Replacement solvent

a.    Prepare beaker glass and fill it with 7 ml calcium acetate. Then add 40 ml alcohol 95%. Observe gel which is formed.

b.    Pour calcium acetate gel into burning cup. Then burn that gel. Observe and write down what happened.

2.    Mix watery solutions

a.    Pour 3 ml AgNO₃ solution 0,1 M into reaction tube and add 5 ml HCl solution 0,1 M.

b.    Mix it and write down the observation result.

B.    Make colloids with dispersion method:

1.    Making sol sulfur

a.    Grind ½ spoon of sugar and ½ spoon of sulfur powder in mortar and pestle porcelain.

b.    Take ½ parts from that mixture and add ½ spoon of sugar into it. Grind again.

c.    Do the same procedure until 4 times.

d.    Take 2 spatula of grind mixture into ½ parts water in reaction tube.

e.    Take 2 spatula sugar and sulfur powder into ½ parts water in another reaction tube.

f.     Observe it and compare each other.

g.    Radiate it with flashlight and write down the result.

2.    Making sol gel

a.    Pour 1 spatula of gel powder into reaction tube which is filled water about ½ parts.

b.    Warm and stir it with spatula.

c.    Then, refrigerate it.

d.    Observe and write down the result.

3.    Making emulsion

a.    Pour about 1 ml kerosene and 5 ml water into reaction tube.

b.    Shake the reaction tube strongly.

c.    Wait about 1-3 minutes. Observe what happened with it.

d.    Drip 25 drop detergent solution and shake it again.

e.    Wait about 1-3 minutes. Observe what happened and write down the result.

VI.         RESULT

1.    Gel from 7 ml calcium acetate and 40 ml alcohol 95% can disseminate light.

2.    Mixture from 3 ml AgNO₃ solution and 5 ml HCl can disseminate light.

3.    Mixture between sulfur and sugar that grinding can disseminate light.

4.    Jelly can disseminate light.

5.    Mixture from water, kerosene, and detergent can disseminate light.

VII.       ANALISYS

1.    Replacement solvent

Mixture from 7 ml calcium acetate and 40 ml alcohol 95% formed gel.

a.    Before burning, that gel occur Tyndall effect.

b.    After burning, formed burning remainder.     

2.    Mix watery solutions

After 3 ml AgNO₃ solution 0,1 M are added by 5 ml HCl 0,1 M formed AgCl precipitation and HNO₃ solution. When it is given light Tyndall effect occur.

3.    Making sol Sulfur

a.    Making sol sulfur with grinding sulfur and sugar will produce colloid that occur Tyndall effect.

b.    Mix sulfur and sugar without grinding will produce suspension that Tyndall effect didn’t occur.

4.    Making sol of jelly

The mixture form jelly and occur Tyndall effect.

5.    Making emulsion

a.    When kerosene is mixed with water, Tyndall effect didn’t occur.

b.    When that mixture is added by detergent it occur Tyndall effect.

VIII.    CONCLUSION

The mixtures that include colloid are;

1.   The mixture between AgNO₃ solution and HCl solution that form AgCl (colloid) and HNO_3.

2.    Gel that formed from calcium acetate and alcohol.

3.    Sol sulfur that grinded.

4.    Jelly.

5.    Mixture between kerosene, water and detergent.