Question

Calculate the [CH3NH3+] of a 7.02×10-3 M solution of the weak base CH3NH2 (make an approximate calculation assuming that initial concentration is equal to the equilibrium concentration). Round your answer to 3 significant digits.

CH3NH2 + H2O = CH3NH3+ + OH-

Answer 1

Set up an ICE chart and substitute into the Kb expression.

Kb = ?? = (CH3NH3^+)(OH^-(/(CH3NH2)
(CH3NH3^+) = (OH^-) = x
((CGH3NH2) = 7.02 x 10^-3