for the reaction at 20 C
NH3 (aq) + H+ (aq) <----> NH4+(aq) the equilibrium constant is calculated to be K=4.5 x 108
the equilibrium constant is the ratio of the concentration product of the product and the reactant of a particular reaction.
i.e. Kc = [NH4+]/[NH3][H+] where Kc is 4.5e8.
To calculate the equilibrium constant for a reaction, you need to know the balanced equation and the concentrations (or partial pressures) of the reactants and products at equilibrium. In this case, the equation is:
NH3 (aq) + H+ (aq) ⇌ NH4+(aq)
The equilibrium constant (K) expression for this reaction can be written as:
K = [NH4+(aq)] / ([NH3(aq)] * [H+(aq)])
Given that the equilibrium constant (K) for the reaction is 4.5 x 10^8, it indicates that the concentrations of the products, NH4+ and the reactants, NH3 and H+, are related in the following way:
4.5 x 10^8 = [NH4+(aq)] / ([NH3(aq)] * [H+(aq)])
However, to determine the actual concentrations at equilibrium, you would need additional information such as the initial concentrations or the extent of reaction.