Name the gas evolved in each of the following cases : Action of heat on magnesium carbonate.

Explanation

To solve the question regarding the gas evolved during the action of heat on magnesium carbonate, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Compound**: The compound in question is magnesium carbonate, which has the chemical formula \( \text{MgCO}_3 \).

2. **Understand the Process**: When magnesium carbonate is heated, it undergoes a thermal decomposition reaction. This means that it breaks down into simpler substances when subjected to heat.

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