Question

What happens when 

(a) ZnCO₃ is heated in the absence of oxygen? 

(b) a mixture of Cu₂O and Cu₂S is heated?

Answer 1

a) When ZnCO₃ is heated in the absence of oxygen Zinc Oxide and Carbon-di-oxide are liberated. 

ZnCO₃ → ZNO + CO₂ 

b) When a mixture of Cu₂O and Cu₂S is heated we get pure copper 

2Cu₂O+ Cu₂S → 6Cu + SO₂