Calculate the pOH of a solution that contains 3.9 x 10-5 M H3O + at 25°C.

a. 4.41

b. 9.59

c. 8.59

d. 0.59

e. 5.41

Option b. 9.59

Explanation:

First, let us calculate the pH. This is illustrated below:

[H3O+] = 3.9 x 10-5 M

pH = - Log [H3O+]

pH = - Log [3.9 x 10-5]

pH = 4.41

Recall: pH + pOH = 14

4.41 + pOH = 14

Collect like terms

pOH = 14 - 4.41

pOH = 9.59