What is the pH of a 8.4 x10^-5 M LiOH solution?

Question

(a)What is the pH of a 8.4x10^-5 M LiOH solution?

(b) What is the H3O+ concentration of the solution?

M

(c) What is the pOH of the solution?

Answer 1

(It's easier to do these problems in different orders)

Since LiOH is a strong base, it dissociates completely. Therefore, [LiOH] = [OH-] = 8.4 x 10^-5 M

pOH = - log[OH-]

pOH = -log(8.4 x 10^-5)

pOH = 4.075

pH + pOH = 14

pH + 4.075 = 14

pH = 14 - 4.075

pH = 9.925

pH = -log[H30+]

9.925 = -log[H30+]

[H30+] = 1.19 x 10^-10 M

Basically, all this is is memorization of formulas and ways to apply them. Hope I helped :)