Question

In water at 25°C, which of the following is the most basic solution?
a) pH = 3
b) pH = 0
c) [OH-] = 10-13 M
d) [H3O+] = 10-13 M

My assumption is is OH- 10^-13, but I am not confident, is this some sort of trick question?

Answer 1

I don't think it's a trick question. I think the thing to do is to convert all to the same units; i.e., either all H^+, all OH^-, or all pH or pOH. Let's convert all to pH.
a) is pH = 3
b) is pH = 0
c) is OH^- = 10^-13 which makes pOH 13 and pH 1
d) is H3O^+= 10^-13 = pH 13
Since pH is 0 to 14 on the scale with pH = 1 the most acid and pH = 14 most basic so the answer is .........