Preparation of Lyophilic Sol - Egg albumin

In this article, we have discussed a step-by-step procedure to perform an experiment which will help you understand how to prepare colloidal solution of Egg albumin. Carefully read the article to understand the aim, procedure and the materials required to perform the experiment. Conduct the experiment and try to match your result with this.

Table of Contents

• • Aim
  • Theory
  • Materials Required
  • Procedure
  • Precautions
  • Viva Voce

Aim:

To prepare lyophilic sol of egg albumin.

Theory:

Lyophilic sol can also be obtained from egg albumin present in eggs. When the egg albumin is mixed with cold water we get lyophilic sol. The sol obtained is very stable and is unaffected by the traces of impurities present in it.

Materials Required:

The apparatus required for this experiment are as follows:

• • • 1. Glass rod
      2. Filter paper
      3. Porcelain dish
      4. Beaker of about 50 to 250 mL
      5. Tripod stand
      6. Distilled water
      7. Burner
      8. Pestle and mortar
      9. Wire gauze
      10. Funnel
      11. 500 mg soluble starch

Procedure:

• • • 1. With the help of a glass rod, break the outer shell of the egg and collect the colourless liquid (egg albumin) and the yellow yolk in a porcelain dish.
      2. Take a beaker of volume 250 mL and prepare 100 mL NaCl solution of 5% (w/v).
      3. Pipette out the albumin and pour it into the beaker containing sodium chloride solution with constant stirring.
      4. Stir it for 15-20 minutes to ensure that the sol is prepared well.
      5. With the help of filter paper and funnel, filter the contents of the beaker.
      6. Label the filtrate as egg albumin sol.

Precautions:

• • • • The apparatus used for this experiment should be washed with distilled water and dried.
      • Always use distilled water to prepare egg albumin sol.
      • Egg albumin sol is prepared at room temperature as egg albumin precipitates at a higher temperature.
      • Make sure to separate the egg albumin and yellow yolk before mixing it with the sodium chloride solution.
      • Constantly stir the mixture in the beaker while adding egg albumin to prepare egg albumin sol.

Viva Voce:

1. How do you identify egg yolk and egg albumin?

Ans: The yellow colour present in the egg is called egg yolk whereas the colourless liquid present in the egg is called egg albumin.

2. How to extract egg albumin from the mixture of egg yolk and egg albumin?

Ans: Break the shell of the egg into a porcelain dish and pipette out the colourless liquid.

3. What is Egg albumin mixed with?

Ans: Distilled water.

4. Constant stirring is required while adding the Egg albumin to the sodium chloride solution. True or false?
Ans: True.