Name the gas evolved in each of the following cases : Addition of concentrated sulphuric acid to sodium chloride.

Explanation

To determine the gas evolved when concentrated sulfuric acid is added to sodium chloride, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants in this case are sodium chloride (NaCl) and concentrated sulfuric acid (H2SO4).

2. **Write the Chemical Reaction**: When concentrated sulfuric acid is added to sodium chloride, a chemical reaction occurs. The balanced chemical equation for this reaction is:
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