What concentration of CH3NH3Br is necessary to prepare a pH = 10.00 buffer solution assuming the base concentration is 0.49 M (Kb for CH3NH2 = 4.4 x 10-4). In M

1 answer

pH = pKa + log(base)/(acid)
You have Kb, convert that to pKb, then to pKa by pKa + pKb = pKw = 14.

(CH3NH3B) is the acid.
pH = 10.0
(base) = 0.49M
Solve for (CH3NH3Br)