Balance the chemical equation by the oxidation number method.
(viii) `MnO_(2) + HCl to MnCl_(2) + Cl_(2) + H_(2)O`

Explanation

To balance the chemical equation \( \text{MnO}_2 + \text{HCl} \rightarrow \text{MnCl}_2 + \text{Cl}_2 + \text{H}_2\text{O} \) using the oxidation number method, follow these steps:

### Step 1: Assign Oxidation Numbers
- In \( \text{MnO}_2 \), manganese (Mn) has an oxidation state of +4 (since O is -2, and there are two O atoms).
- In \( \text{HCl} \), chlorine (Cl) has an oxidation state of -1.
- In \( \text{MnCl}_2 \), Mn has an oxidation state of +2 (since Cl is -1, and there are two Cl atoms).
- In \( \text{Cl}_2 \), Cl has an oxidation state of 0 (as it is in its elemental form).
- In \( \text{H}_2\text{O} \), oxygen has an oxidation state of -2, and hydrogen (H) has an oxidation state of +1.
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