The Ellingham diagram for a number of metallic sulphides is shown below. [SEE DIAGRAM] — Metallurgy and Isolation of Elements Chemistry Question

💡 Solution & Explanation

Step 1: Highly electropositive metals (like alkali and alkaline earth metals) have a very high affinity for oxygen and carbon. Step 2: At the high temperatures required for carbon reduction, these metals readily react with the reducing agent (carbon) to form very stable ionic metal carbides rather than the free metal. Step 3: Consequently, carbon reduction is not a commercially viable method for extracting highly electropositive metals. Thus, the correct option is (b).