Question

The nature of zinc powder and Cobalt (II )oxide is heated the following reaction occurs ;

Answer 1

1) The metal which reduces the other compound is the one higher in the reactivity. So in this case it is $\mathrm{Zn}$.

2) The substance which brings about reduction while itself getting oxidised (that is losing electrons) is called a reducing agent. Here, $\mathrm{Zn}$ is the reducing agent and reduces Cobalt Oxide to Cobalt while itself getting oxidised to Zinc oxide.