Question

Which one of the following reactions is different from the remaining three?

• A. NaCl + AgNO₃ → AgCl + NaNO₃
• B. CaO + H₂O → Ca(OH)₂
• C. KNO₃ + H₂SO₄ → KHSO₄ + HNO₃
• D. ZnCl₂ + H₂S → ZnS + 2HCl

Answer 1

The Correct Option is B

1: This is a double displacement reaction (precipitation reaction) where sodium chloride reacts with silver nitrate to form silver chloride and sodium nitrate.
2: This is a combination reaction where calcium oxide reacts with water to form calcium hydroxide. This is different from the other reactions, which involve displacement or exchange of ions.
3: This is an acid-base reaction where nitric acid (\(HNO_3\)) reacts with sulfuric acid (\(H_2SO_4\)) to form potassium bisulfate and nitric acid.
4: This is a double displacement reaction where zinc chloride reacts with hydrogen sulfide to form zinc sulfide and hydrochloric acid.
The Different Reaction: Option (B) is a combination reaction, whereas the others are displacement or exchange reactions.