Question

Which of the following is not an example of roasting?

• A. $2ZnS + 3O_2 \to 2ZnO + 2SO_2$
• B. $2PbS + 3O_2 \to 2PbO + 2SO_2$
• C. $2Cu_2S + 3O_2 \to 2Cu_2O + 2SO_2$
• D. $2Cu_2O + Cu_2S \to 6Cu + SO_2$

Answer 1

Answer: (D)

$2Cu_2O + Cu_2S \to 6Cu + SO_2$

Answer 2

It is an example of auto-reduction in which unoxidised copper sulphide reduces copper oxide.