In the extraction process of copper, the product obtained after carrying out the reactions
(i) 2 Cu₂ S+3 O₂ → 2 Cu₂ O+2 SO₂
(ii) 2 Cu₂ O+Cu₂ S → 6 Cu+SO₂ is called

Solution

Chemistry ma’am · 4 steps

Look at what the escaping SO₂ does to the copper: it blisters the surface, and that gives the name.

1. Where this happens. Copper matte, mostly Cu₂S with some FeS, is heated in a Bessemer converter with a blast of air. The iron goes off as slag first, and then these two reactions convert Cu₂S into copper.
2. Self-reduction. Part of the Cu₂S is oxidised to Cu₂O. That Cu₂O then reacts with the remaining Cu₂S, so no outside reducing agent like carbon is needed.

   2Cu₂O + Cu₂S → 6Cu + SO₂ ↑

3. Why blisters. The SO₂ gas escapes as the molten copper cools and solidifies. It leaves bubbles on the surface, giving it a blistered look. This copper is about 98% pure.
4. So. The product is blister copper, option (b). It is later refined further, usually by electrolysis.

The idea to keep. In copper extraction: concentrated ore is roasted and smelted into matte (Cu₂S + FeS), then converted by self-reduction into blister copper, and finally refined electrolytically.

Answer from the NTA final answer key. Solution by PrepWiser.