Chemistry Question About Acid-Base Reactions?

Question

A 0.053g sample of Ca(OH)2 is dissolved in enough water to make 115mL of solution. Calculate the [H3O] and [OH] for this solution.

PLEASE include step-by-step instructions.

Answer 1

Molarity = (0.053/74)/.115 = 6.23 x 10^-3 M

of OH- = 12.46 x 10^-3

pOH = -log(12.46x10^-3) = 1.9

pH = 12.1