Question

The oxide which can react with HCl as well as KOH to give corresponding salt and water is

• A. CuO
• B. Al₂O₃
• C. Na₂O
• D. K₂O

Answer 1

The Correct Option is B

Step 1: Identify oxide reactivity:
An oxide reacting with both hydrochloric acid (HCl) and potassium hydroxide (KOH) is amphoteric. Amphoteric oxides react with both acids and bases, producing salts and water.

Step 2: Evaluate options:
- Al₂O₃ (Aluminum oxide):
Aluminum oxide (Al₂O₃) is amphoteric. It reacts with HCl to form aluminum chloride and with KOH to form soluble aluminate salts.
Reaction with HCl:

  Al2O3 + 6HCl → 2AlCl3 + 3H2O  

Reaction with KOH:

  Al2O3 + 2KOH + 3H2O → 2KAl(OH)4  

Thus, it reacts with both HCl and KOH, yielding the respective salt and water.

- Other oxides (e.g., basic Na₂O, acidic CO₂):
Basic oxides react only with acids, and acidic oxides react only with bases. Neither reacts with both.

Step 3: Conclusion:
Al₂O₃ is the oxide that reacts with both HCl and KOH to form the corresponding salt and water.