Chapter 14, Problem 28E

For each reaction, indicate which elements are oxidized and which are reduced:

$\begin{array}{l}\text{a}{\text{. WO}}_{\text{3}}{\text{+3H}}_{\text{2}}\to {\text{W+3H}}_{\text{2}}\text{O}\\ \text{b}{\text{. 2Na+Cl}}_{\text{2}}\to \text{2NaCl}\\ \text{c}{\text{. 2Fe}}_{\text{2}}{\text{O}}_{\text{3}}\text{+3C}\to {\text{4Fe+3CO}}_{\text{2}}\end{array}$