Question

Identify the product obtained on roasting of concentrated zinc blende at about 1200 K?

• A. Zinc Sulphate
• B. Zinc Oxide
• C. Zinc Spelter
• D. Zinc Carbonate

Hint:

Zinc oxide is formed by the roasting of zinc sulfide (zinc blende) in the presence of oxygen.

Answer 1

The Correct Option is B

Step 1: Understanding the roasting of zinc blende.
Roasting of zinc blende (ZnS) involves heating the ore in the presence of oxygen. At around 1200 K, zinc sulfide (ZnS) is oxidized to form zinc oxide (ZnO) and sulfur dioxide (SO₂). The reaction is as follows: \[ 2ZnS + 3O_2 \rightarrow 2ZnO + 2SO_2 \] Thus, the primary product of roasting zinc blende is zinc oxide.
Step 2: Analyzing the options.
(A) Zinc Sulphate: Incorrect. Zinc sulfate is not formed by roasting but rather by reacting zinc oxide with sulfuric acid.
(B) Zinc Oxide: Correct — Zinc oxide is the product obtained from the roasting of zinc blende.
(C) Zinc Spelter: Incorrect. Zinc spelter is the product obtained from the reduction of zinc oxide in a furnace, not from roasting.
(D) Zinc Carbonate: Incorrect. Zinc carbonate is not produced during roasting, but may form under certain conditions if carbon dioxide is present.
Step 3: Conclusion.
The correct answer is (B) Zinc Oxide, as it is the product obtained from roasting concentrated zinc blende.