What happens when `H_(3) PO_(3)` is heated ?

Explanation

**Step-by-Step Solution:**

1. **Identify the Compound**: The compound in question is orthophosphorus acid, which is represented as \( H_3PO_3 \).

2. **Heating the Compound**: When \( H_3PO_3 \) is heated, it undergoes a chemical reaction known as disproportionation.

3. **Understanding Disproportionation**: A disproportionation reaction is a specific type of redox reaction where the same element is both oxidized and reduced. In this case, phosphorus in \( H_3PO_3 \) is the element undergoing these changes.

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