Write chemical equations for the following processes :
(i) Chlorine reacts with a hot concentrated solution of sodium hydroxide
(ii) Orthophosphorous acid is heated
(iii) `PtF_(6)` and xenon are mixed together

Explanation

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### (i) Chlorine reacts with a hot concentrated solution of sodium hydroxide

1. **Identify the reactants**: Chlorine (Cl₂) and sodium hydroxide (NaOH).
2. **Determine the conditions**: The solution of sodium hydroxide is hot and concentrated.
3. **Predict the products**: When Cl₂ reacts with hot concentrated NaOH, it produces sodium chloride (NaCl), sodium chlorate (NaClO₃), and water (H₂O).
4. **Write the unbalanced equation**:
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