H2SO4(aq) + Na2CO3(s) = Na2SO4(aq) + H2O + CO2(g)

So, when dilute sulphuric acid reacts with sodium carbonate, carbon dioxide gas is evolved.

The gas evolved when dilute sulphuric acid acts on sodium carbonate is carbon dioxide. This reaction is a type of acid-base reaction, where the acid (sulphuric acid) reacts with the base (sodium carbonate) to form a salt (sodium sulphate), water, and carbon dioxide.

Reaction Equation:

H2SO4 + Na2CO3 → Na2SO4 + H2O + CO2

Explanation:

- Dilute sulphuric acid (H2SO4) contains hydrogen ions (H+) which act as an acid.
- Sodium carbonate (Na2CO3) contains carbonate ions (CO32-) which act as a base.
- When these two compounds are mixed, the hydrogen ions from the acid react with the carbonate ions from the base to form water and carbon dioxide gas.
- The remaining products are sodium sulphate and water.
- The carbon dioxide gas can be identified by its effervescence, or bubbling, when the acid is added to the sodium carbonate.

Conclusion:

In conclusion, the gas evolved when dilute sulphuric acid acts on sodium carbonate is carbon dioxide. This reaction is a type of acid-base reaction, where the acid reacts with the base to form a salt, water, and carbon dioxide gas.