Question

[CH₃NH₂ + H₂O ⇌ CH₃NH⁻+ H₃O⁺] Determine the dissociation constant for the following reaction if the equilibrium of the reactants and products are: 2M, 2.3M, and 1.6M for the CH₃NH₂, CH₃NH⁻, and H₃O⁺, respectively. Is it a strong acid, a weak acid, a strong base, or a weak base?

Answer 1

Equilibrium dissociation constant, $K_a=\dfrac{[CH_3NH^-][H_3O^+]}{[CH_3NH_2]}$

$K_a=\dfrac{2.3\times1.6}{2}=1.84$