Exams › JEE Advanced › Chemistry

When Cu₂S is heated, which of the following substances produces copper metal?

1. CuFeS₂
2. CuO
3. Cu₂O
4. CuSO₄

Correct answer: Cu₂O

Solution

In the self-reduction (bessemerisation) step copper is obtained by the reaction 2Cu2O + Cu2S -> 6Cu + SO2. Hence heating Cu2S with Cu2O yields copper metal, so the answer is Cu2O, not CuO.

Related JEE Advanced Chemistry questions

• Sulfide ores are common for the metals -
• Galena, a lead ore, undergoes partial oxidation when air is passed through it at elevated temperatures. Afterward, air flow is stopped, and heating continues in a sealed furnace, allowing self-reduction to occur. What is the mass (in kg) of lead formed per kilogram of oxygen used? (Atomic masses in g/mol: O = 16, S = 32, Pb = 207)
• Identify the chemical compositions of calamine, malachite, magnetite, and cryolite in the correct sequence.
• A mixture of cations is treated with H2S gas in an acidic solution. Which group of cations will form insoluble sulfide precipitates under these conditions?
• Which of the following pairs of metals is correctly matched with its commercial extraction method?
• Identify the incorrect statement among the following about metallurgical processes.

⚔️ Practice JEE Advanced Chemistry free + battle 1v1 →