If you mix ammonium chloride with dilute sulphuric acid there will not be any effective reaction even if the mixture is heated...but if a mixture of pure (solid) ammonium chloride and concentrated sulphuric acid is heated, hydrogen chloride gas will evolve.

Reaction between Sulphuric Acid and Ammonium Chloride

When sulphuric acid (H2SO4) reacts with ammonium chloride (NH4Cl), a chemical reaction takes place. This reaction is an example of an acid-base reaction and involves the formation of a salt along with the release of gases.

The reaction can be summarized by the following equation:

H2SO4 + 2NH4Cl → (NH4)2SO4 + 2HCl

Formation of Ammonium Sulphate

When sulphuric acid reacts with ammonium chloride, ammonium sulphate ((NH4)2SO4) is formed. Ammonium sulphate is a white crystalline solid that is commonly used as a fertilizer due to its high nitrogen content. The formation of ammonium sulphate can be represented by the following equation:

H2SO4 + 2NH4Cl → (NH4)2SO4 + 2H2O

Release of Hydrochloric Acid Gas

In addition to the formation of ammonium sulphate, the reaction also produces hydrochloric acid (HCl) gas. Hydrochloric acid is a strong acid and is released as a gas in this reaction. The release of hydrochloric acid gas is represented by the following equation:

H2SO4 + 2NH4Cl → (NH4)2SO4 + 2HCl

Observations

When sulphuric acid is added to ammonium chloride, some key observations can be made:

1. Effervescence: As the reaction takes place, effervescence occurs due to the release of hydrochloric acid gas. This can be observed as bubbles or fizzing.

2. Heat Release: The reaction between sulphuric acid and ammonium chloride is exothermic, meaning it releases heat. This can be felt by touching the reaction mixture, which will become warmer.

3. Formation of White Solid: Ammonium sulphate, the salt formed in the reaction, is a white solid. It may be observed as a precipitate or solid particles in the reaction mixture.

Conclusion

In summary, when sulphuric acid reacts with ammonium chloride, ammonium sulphate is formed along with the release of hydrochloric acid gas. This reaction is commonly used in laboratories and industrial processes. It is important to note that handling sulphuric acid and hydrochloric acid should be done with caution due to their corrosive nature.