What happens when
(a) ZnCO3 is heated in the absence of oxygen?
Ans. When zinc carbonate is heated in the absence of oxygen, we get zinc oxide and carbon dioxide.
ZnCO3 → ZnO + CO2
(b) a mixture of Cu2O and Cu2S is heated?
Ans. When a mixture of copper oxide and copper sulphide is heated, we get pure copper.
2Cu2O + Cu2S → 6Cu + SO2
