Chapter 18, Problem 91AP

. For each of the following oxidation-reduction reactions of

metals with nonmetals, identify which element is oxidized and

which is reduced.

a. $\text{3Zn}\left(\text{s}\right)+{\text{N}}_{\text{2}}\left(\text{g}\right)\to {\text{Zn}}_3{\text{N}}_{\text{2}}\left(\text{s}\right)$   b. $\text{Co}\left(\text{s}\right)+\text{S}\left(s\right)\to \text{CoS}\left(\text{s}\right)$   c. $\text{4K}\left(s\right)+{\text{O}}_{\text{2}}\left(\text{g}\right)\to {\text{2K}}_{\text{2}}\text{O}\left(\text{s}\right)$   d. $\text{4Ag}\left(\text{s}\right)+\text{O}\left(\text{g}\right)\to {\text{2Ag}}_{\text{2}}\text{O}\left(\text{s}\right)$