Chemistry

Problem

Which of the following reaction(s) occur during calcination? a.

\text{CaCO}_3 \longrightarrow \text{CaO} + \text{CO}_2

4\text{FeS}_2 + 11\text{O}_2 \longrightarrow 2\text{Fe}_2\text{O}_3 + 8\text{SO}_2

2\text{Al}(\text{OH})_3 \longrightarrow \text{Al}_2\text{O}_3 + 3\text{H}_2\text{O}

\text{CuS} + \text{CuSO}_4 \longrightarrow 2\text{Cu} + 2\text{SO}_2