A solution with a pH of 7 has a [OH1-] of?

pH=7, pOH=14-pH

no, not correct, pOH is 7.
1E-7 is the OH concentration
P OH=-log (OH)

so its 7m?

7M??

Your original answer of 1E-7M = (OH^-) is correct.

Yes, that is correct. To understand how to arrive at this answer, let's go through the explanation step by step.

The pH of a solution is a measure of its acidity or alkalinity. It is defined as the negative logarithm (base 10) of the concentration of hydrogen ions, [H+]. The pH scale ranges from 0 to 14, with 7 being considered neutral. A pH below 7 indicates acidity, while a pH above 7 indicates alkalinity.

In neutral solutions, the concentration of hydrogen ions ([H+]) is equal to the concentration of hydroxide ions ([OH-]). So, in a solution with a pH of 7, the concentration of both [H+] and [OH-] is 10^-7 M.

So, to answer your question, a solution with a pH of 7 has an [OH-] concentration of 1 x 10^-7 M.