Question

What are the concentrations of [H+] and [OH-] in each of the following. Determine the pH and pOH for each solution.
A. 1.25 M HCl
B. 0.25 M NaOH
C. 0.035 M Ca(OH)2
D. 0.50 M HNO3

I know how to do the pH and pOH I just do not know how to figure out the both concentrations.

Answer 1

1.25 M HCl = 1.25 M H^+; therefore,
Kw = 1 x 10^-14 = (H^+)(OH^-). You know Kw and (H^+). Calculate OH^-

NaOH = 0.25 M = OH^-
Kw = (H^+)(OH^-). YOu know Kw and OH, calculate H^+.