13. Es una sal oxisal y haloidea respectivamente: a) $\mathrm{NaH}-\mathrm{K}_{2} \mathrm{O}$ b) $\mathrm{Li}_{2} \mathrm{O}-\mathrm{HgO}$ c) $\mathrm{MgO}-\mathrm{N}_{2} \mathrm{O}_{3}$ d) $\mathrm{K}_{2} \mathrm{CO}_{3}-\mathrm{AgCl}$ e) $\mathrm{CrO}_{3}-\mathrm{Al}_{2} \mathrm{CO}_{3}$

d) $\mathrm{K}_{2} \mathrm{CO}_{3}-\mathrm{AgCl}$

Explanation: The compound $\mathrm{K}_{2} \mathrm{CO}_{3}$ is a salt because it is formed by the combination of a metal cation (potassium, $\mathrm{K}^{+}$) and a polyatomic anion (carbonate, $\mathrm{CO}_{3}^{2-}$). The compound $\mathrm{AgCl}$ is a haloide because it is formed by the combination of a metal cation (silver, $\mathrm{Ag}^{+}$) and a halogen anion (chloride, $\mathrm{Cl}^{-}$). Therefore, the pair $\mathrm{K}_{2} \mathrm{CO}_{3}-\mathrm{AgCl}$ consists of a salt (oxisal) and a haloide, respectively.