Answer:
Option B.
Kb = [CH3NH3+] [OH-] / [CH3NH2]
Step-by-step explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
CH3NH2(aq) + H2O(l) <=> CH3NH3+(aq) + OH- (aq)?
The expression for the equilibrium constant, Kb is simply the ratio of the concentration of the products raised to their coefficient to the concentration of the reactants raised to their coefficient.
Thus, the expression for the equilibrium constant, Kb fo th above reaction can be written as follow:
Kb = [CH3NH3+] [OH-] / [CH3NH2]
Option B gives the correct expression for Kb.