In this experiment, you will make a white insoluble gel.
Things Required:
1/2 teaspoonful of alum
2 teaspoonfuls of household ammonia
1 small baby food jar
Directions:
Fill the jar one-half full with water. Add 1/2 teaspoonful of alum to the water and stir. Stir in 2 teaspoonfuls of ammonia. Allow the solution to stand for five minutes.
This Is What Happens:
The solution turns cloudy and, after standing, a white gel starts to settle to the bottom of the jar.
Science Behind It:
Household ammonia contains ammonium hydroxide. The hydroxide part of the chemical reacts with the aluminium in the alum. One of the products of the reaction between alum and ammonium is the white, insoluble gel called aluminium hydroxide.
