Chapter 7, Problem 91E

Classify each chemical reaction as a synthesis, decomposition, single-displacement, or double-displacement reaction.

a. ${\text{K}}_{\text{2}}\text{S}\left(aq\right)+\text{Co}{\left({\text{NO}}_{\text{3}}\right)}_2\left(aq\right)\to 2{\text{ KNO}}_{\text{3}}\left(aq\right)+\text{CoS}\left(s\right)$

b. $3{\text{ H}}_{\text{2}}\left(g\right)+{\text{N}}_{\text{2}}\left(g\right)\to 2{\text{ NH}}_{\text{3}}\left(g\right)$

c. $\text{Zn}\left(s\right)+{\text{CoCl}}_{\text{2}}\left(aq\right)\to 2{\text{ ZnCl}}_{\text{2}}\left(aq\right)+\text{Co}\left(s\right)$

d. ${\text{CH}}_{\text{3}}\text{Br}\left(g\right)\underset{\text{UV light}}{\to }{\text{CH}}_{\text{3}}\left(g\right)+\text{Br}\left(g\right)$