Determine the pOH of a 0.188 M NH₃ solution at 25°C.The K_bof NH₃ is 1.76 × 10^-5. A) 5.480 B) 2.740 C) 8.520 D) 11.260 E) 12.656

Question

Quizplus · Accepted Answer

First, we need to find the concentration of hydroxide ions (OH-) in the solution using the ion product constant of water (Kw = 1.0 × 10^-14 at 25°C):

Kw = [H+][OH-] = 1.0 × 10^-14 
[OH-] = Kw/[H+] = 1.0 × 10^-14/10^-14.73 (pH = 0.73 from pOH = 14 - pH) 
[OH-] = 1.0 × 10^-0.27 = 0.501 M

Next, we can find the pOH of the solution:

pOH = -log[OH-] 
pOH = -log(0.501) 
pOH = 0.301

Therefore, the answer is B (2.740).

Determine the POH of a 0