What substance forms an acid when heated with another substance?
- ASodium chloride
- BPotassium chloride
- CRubidium chloride
- DAmmonium chloride
Show answer and explanation
Correct answer: (d) Ammonium chloride
Explanation
Ammonium chloride (NH₄Cl) gives an acid when heated. On its own it splits into ammonia and hydrogen chloride (NH₄Cl → NH₃ + HCl), and heated with concentrated sulphuric acid it gives off HCl gas.
The chlorides of sodium, potassium and rubidium are stable salts that do not give an acid on heating.