An aqueous basic solution has a concentration of 0.050 M and K_b is 4.4 × 10^-4.What is the concentration of hydronium ion in this solution (M)? A)2.2 × 10^-13 B)2.2 × 10^-12 C)2.9 × 10^-13 D)0.050 E)4.5 × 10^-13

Question

Quizplus · Accepted Answer

Kw = [H3O+][OH-] = 1.0 x 10^-14
Kb = Kw/Ka = 1.0 x 10^-14 / 4.4 x 10^-4 = 2.27 x 10^-11

Additionally, Kb = [BH+][OH-]/[B]

Assuming that the concentration of OH- is approximately equal to the concentration of BH+,

Kb = [OH-]^2 / [B]

2.27 x 10^-11 = [OH-]^2 / 0.05

[OH-] = 2.2 x 10^-6

pOH = -log[OH-] = 5.66

pH = 14 - pOH = 8.34

[H3O+] = 10^-pH = 2.2 x 10^-9 = 2.2 x 10^-12 M

An Aqueous Basic Solution Has a Concentration of 0