Question

What A chemistry graduate student is given 250. mL of a 0.40 M dimethylamine (CH), NH solution. Dimethylamine is a weak base with K -5.4 x 10 mass of (CH), NH,CI should the student dissolve in the (CH), NH solution to turn it into a buffer with pH 10.327 You may assume that the volume of the solution doesn't change when the (CH), NH,Cl is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits. X 5 ?

Answer 1

a For a bubben solution made of a weak base and its salt, the butter equation is - [salt] pOH = pky + log [base Given, poH = 14- pH = 14 – 10.32 = 3.68 pky = -log (5.48169) = 3.268 [base] = 0.40 M :3.68 = 3.268 + log 0.90 salt] Tsalt] ► log Love = 0.412 → [salt] = 1,033 M So, 1000 ml bubben solution contains 1.033 mol (CH3)2NH, el 250 1 1 1 1.033 X250 mol (CH2), NH, 1000g = 1.033* 81.45 g (CH3)N71 a = 21.034 g (CH3)2NH4C 21 9] (twenty one gram) ANSWER -