Determine the pH of the following base solutions. (Assume that all solutions are at 25°C and the ion-product constant of water,
Kw,
is 1.01 ✕ 10−14.)
1.46 ✕ 10−2 M NaOH

Question

Determine the pH of the following base solutions. (Assume that all solutions are at 25°C and the ion-product constant of water, 
Kw,
 is 1.01 ✕ 10−14.)
1.46 ✕ 10−2 M NaOH

cometailcane · Answer

So what I did was -log(1.46x10^-2) and got 1.84. Then I did 14-1.84 to get 12.16.
I tried to answer 12.2 because of sig figs but it was wrong.

aaronq · Answer

that value should be right, what does the answer key say?

cometailcane · Answer

I have a certain number of tries for the answer so all I know is that it was wrong

aaronq · Answer

The answer is correct though, i think there might be a problem with the answer they wrote. Can you email someone (like your teacher) about this?

cometailcane · Answer

I can do that. Also what about for 0.0065 M Al(OH)3?
I did -log(3x0.0065) = 1.71 and then 14-1.71 = 12

cometailcane · Answer

My teacher said to: Divide Kw by the molarity of NaOH and then plug that in the -log formula.