Chemistry help!!!

Question

1. Determine the [OH^-], pH, and pOH of a solution with a [H^+] of 9.4 x 10^-7 M at 25 °C.
2. Determine the [H^+] , pH, and pOH of a solution with an [OH^-] of 2.4 x 10^-13 M at 25 °C.
3. Determine the [H^+], [OH^-] , and pOH of a solution with a pH of 3.73 at 25 °C.
4. Determine the [H^+], [OH^-] , and pH of a solution with a pOH of 4.25 at 25 °C.

Answer 1

You need to learn the following relationships, and then you can do any and all of these problems:

1. [H⁺][OH^-] = Kw = 1x10^-14
2. pH = -log [H⁺] and pOH = -log [OH^-]
3. pH + pOH = 14

Determine the [OH^-], pH, and pOH of a solution with a [H^+] of 9.4 x 10^-7 M at 25 °C.

[OH^-] = Kw/[H⁺] = 1x10^-14/9.4x10^-7 = 1.06x10^-8 M

pH = 14 - pOH and pOH = -log [OH^-] = -log 1.06x10^-8 = 7.97. pH = 14 - 7.97 = 6.03 = pH

pOH = -log [OH-] = 7.97. pOH also = 14 - pH = 14 - 6.03 = 7.97

You can do the rest using the above relationships. Practice, practice, practice.