A chemistry graduate student is given 125 mL of a 0.90 M diethylamine ((C2H5)2NH) solution. Diethylamine is a weak base with Kb=1.3×10^-3. What mass of (C2H5)2NH2Br should the student dissolve in the (C2H5)2NH solution to turn it into a buffer with pH=10.53?
You may assume that the volume of the solution doesn't change the (C2H5)2NH2Br is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.