What happens when :
(i) `PCl_(5)`, is heated (ii) `H_(3)PO_(3)` is heated

Explanation

Let's break down the solution step by step for the given question.

### Step 1: Heating of PCl5
When PCl5 (phosphorus pentachloride) is heated, it undergoes a reversible reaction. The structure of PCl5 consists of three equatorial bonds and two axial bonds.

**Reaction:**
\[ \text{PCl}_5 \rightleftharpoons \text{PCl}_3 + \text{Cl}_2 \]

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