What happens when `H_2PO_3` is heated?

Explanation

When heating `H3PO3` (phosphorous acid), a disproportionation reaction occurs. Here’s a step-by-step breakdown of the process:

### Step 1: Identify the Compound
The compound in question is `H3PO3`, which is phosphorous acid.

### Step 2: Determine the Oxidation State of Phosphorus
To understand what happens when `H3PO3` is heated, we first need to calculate the oxidation state of phosphorus in `H3PO3`.

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