A white powder is used by doctors to support fractured bones.
When this white powder is mixed with water a hard solid mass is obtained. Write a balanced chemical equation for the change.

Explanation

To write a balanced chemical equation for the reaction of plaster of Paris (calcium sulfate hemihydrate) with water, follow these steps:

### Step 1: Identify the Reactants
The white powder used by doctors is plaster of Paris, which has the chemical formula:
\[ \text{CaSO}_4 \cdot \frac{1}{2} \text{H}_2\text{O} \]
This can also be represented as:
\[ \text{CaSO}_4 \cdot \text{H}_2\text{O} \]

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