Give the chemical formula of the following:
a. Plaster of paris, b. Asbestos, c. Hydrolith

Explanation

To answer the question regarding the chemical formulas of Plaster of Paris, Asbestos, and Hydrolith, we can break it down step by step.

### Step 1: Plaster of Paris
- **Definition**: Plaster of Paris is primarily composed of calcium sulfate with water.
- **Chemical Formula**: The chemical formula for Plaster of Paris is \( \text{CaSO}_4 \cdot \frac{1}{2} \text{H}_2\text{O} \) or more commonly written as \( \text{CaSO}_4 \cdot \text{1/2 H}_2\text{O} \). This indicates that for every molecule of calcium sulfate, there is half a molecule of water associated with it.

### Step 2: Asbestos
- **Definition**: Asbestos is a naturally occurring mineral that is a hydrous magnesium silicate.
...