gypsum is insoluble in water. you are asked to purify a sample of gypsum that is contaminated with a soluble salt.

a. The apparatus required to purify gypsum sample are: Bunsen burner, beaker, Filter Funnel, stirring rod, the filter paper.

b. Gypsum is a sulfate mineral that is made up of calcium sulfate dihydrate. Step-by-step instruction to purify gypsum sample is as follows:

1. Add water to the gypsum sample in a beaker.

2. Use the stirring rod to mix the mixture well.

3. Filter off the excess solid from the mixture using the filter paper and filter funnel.

4. Put the filtered mixture over the bunsen burner and evaporate the excess water from the mixture.

5. Allow the hot liquid to cool down and filter it again through the filter paper to get the pure gypsum.

if you mean hydrogen and oxygen then water is the product