Answer
a. Mostly reactants.
b. Mostly reactants.
c. Mostly products.
Work Step by Step
1. Compare the strengths and identify the weaker and stronger acids and bases.
a. $H_3O^+ \gt H_2CO_3$ and $HCO_3^- \gt H_2O$
$H_2CO_3$ is the weaker acid.
$H_2O$ is the weaker base.
$HC{O_3}^-$ is the stronger base.
$H_3O^+$ is the stronger acid.
b. $H_3O^+ \gt N{H_4}^+$ and $NH_3 \gt H_2O$
$NH{_4}^+$ is the weaker acid.
$H_2O$ is the weaker base.
$NH_3$ is the stronger base.
$H_3O^+$ is the stronger acid.
c. $HNO_2 \gt N{H_4}^+$ and $NH_3 \gt N{O_2}^-$
$HNO_2$ is the stronger acid.
$NH_3$ is the stronger base.
$N{O_2}^-$ is the weaker base.
$N{H_4}^+$ is the weaker acid.
2. If the weaker acid and base are on the reactants side, the reaction contains mostly reactants at equilibrium, and vice-versa.
a. $H_2CO_3$ and $H_2O$ on reactants: Mostly reactants.
b. $N{H_4}^+$ and $H_2O$ on reactants: Mostly reactants.
c. $ N{H_4}^+$ and $N{O_2}^-$ on products: Mostly products.