When calculating equilibrium constants, what units should each of the following have?

a$.$ Solutions

b$.$ Gases

Write equilibrium constant expressions for the following reactions:

a$.(N{H}_4{)}_{2}C{O}_3(s)2N{H}_3(g)+C{O}_2(g)+$

c$.N_2{O}_4(g)+O_3(g)N_2{O}_5(g)+O_2(g)H_{2}O(g)$

b$.F{e}^{2+}(aq)+Sn(s)S{n}^{2+}(aq)+Fe(s)$

d$.8H_2(g)+S_8(g)8H_{2}S(g)$

The decomposition of $CaC{O}_3$ is an endothermic process:

$CaC{O}_3(s)CaO(s)+C{O}_2(g)$

a$.$ If more $CaC{O}_3$ is added to a flask in which this equilibrium exists, will the reaction be product$-$favored, reactant$-$favored or unchanged? Explain

b$.$ If the pressure within a flask in which this equilibrium exists decreases, will the reaction be product$-$favored, reactant$-$favored or unchanged? Explain.