Correct match is : — Metallurgy and Isolation of Elements Chemistry Question

💡 Solution & Explanation

Step 1: Copper is commonly extracted from sulfide ores (such as copper pyrites, CuFeS2). During roasting, a portion of the copper sulfide is oxidized to copper(I) oxide (Cu2O). Step 2: At high temperatures, the remaining copper(I) sulfide (Cu2S) reacts directly with the newly formed copper(I) oxide (Cu2O) without requiring any external reducing agent. This reaction is: 2Cu2O + Cu2S -> 6Cu + SO2. Step 3: Because the reduction is accomplished by a reaction between its own sulfide and oxide phases, the process is known as auto-reduction (or self-reduction). This corresponds to option (c).