Barium chloride on reacting with ammonium sulfate forms barium sulfate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?

(i) Displacement reaction

(ii) Precipitation reaction

(iii) Combination reaction

(iv) Double displacement reaction

A) (i) only

B) (ii) only

C) (iv) only

D) (ii) and (iv)

The correct answer is: D) (ii) and (iv) 

Explanation:

The reaction is:

BaCl₂+(NH₄)₂SO₄→BaSO₄↓+2NH₄Cl

• Barium sulfate (BaSO₄) is insoluble in water, so it precipitates → Precipitation reaction
• The cations and anions exchange places → Double displacement reaction 

It is not a displacement or combination reaction, so options (i) and (iii) are incorrect.