Complete the following reactions :
(i) `Mg(NO_3)_2 overset("Heat")to `
(ii) `LiOH overset("Heat")to`
(iii) `Li+HC-=CH to `
(iv) `Na + O_2 to `

Explanation

Let's complete the given reactions step by step:

### (i) Reaction of Magnesium Nitrate upon Heating
1. **Starting Compound**: Magnesium Nitrate, \( \text{Mg(NO}_3\text{)}_2 \)
2. **Heating**: When heated, Magnesium Nitrate decomposes.
3. **Products**: The products formed are Magnesium Oxide \( \text{MgO} \), Nitrogen Dioxide \( \text{NO}_2 \), and Oxygen \( \text{O}_2 \).
4. **Balanced Equation**:
\[
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