JAMB Chemistry 2019 Paper

Concept:The equilibrium constant is the ratio of product concentrations to reactant concentrations, each raised to its stoichiometric coefficient.Explanation:For the reaction $x\mathrm{P} + y\mathrm{Q} \rightleftharpoons m\mathrm{R} + n\mathrm{S}$:The products are $\mathrm{R}$ and $\mathrm{S}$, so they appear in the numerator.Raise each concentration to its coefficient: $[\mathrm{R}]^m[\mathrm{S}]^n$.The reactants are $\mathrm{P}$ and $\mathrm{Q}$, so they appear in the denominator:$[\mathrm{P}]^x[\mathrm{Q}]^y$.Hence, the equilibrium constant is:$$K_c = \frac{[\mathrm{R}]^m[\mathrm{S}]^n}{[\mathrm{P}]^x[\mathrm{Q}]^y}$$Answer:Option D