Question

Prepare crystals of alum.

Answer 1

Preparation of Alum Crystals:

1. Materials Needed:

   • Alum powder
   • Distilled water
   • Heat-resistant container
   • Spoon
   • String
   • Pencil or stick

2. Procedure:

   1. Dissolve Alum: Place 2-3 teaspoons of alum powder in a cup of hot distilled water and stir until fully dissolved.
   2. Cool the Solution: Allow the solution to cool to room temperature.
   3. Prepare String: Tie a string around a pencil or stick, and hang it so that the string is suspended in the solution without touching the sides or bottom.
   4. Wait for Crystals to Form: Place the container in a cool, undisturbed place. After a few days, crystals will start forming on the string.
   5. Collect Crystals: Once sufficient crystals have formed, remove the string and let the crystals dry.

Explanation: The process of dissolving alum in hot water and then cooling allows the alum molecules to slowly come together and form well-defined crystals as the solution becomes supersaturated.