A solution has [H+] = 4.2 x 10-3 M. The [OH-] in this solution is

Group of answer choices
4.2 x 10-3 M
2.4 x 10-12 M
4.2 x 10-11 M
1.0 x 10-14 M
none of these

To find the concentration of hydroxide ions ([OH-]) in a solution, we can use the equation:

[H+] x [OH-] = 1.0 x 10^-14 M^2

Given that the concentration of hydrogen ions ([H+]) is 4.2 x 10^-3 M, we can rearrange the equation to solve for [OH-]:

[OH-] = 1.0 x 10^-14 M^2 / 4.2 x 10^-3 M

Calculating this value gives us [OH-] = 2.4 x 10^-12 M.

Therefore, the correct answer is 2.4 x 10^-12 M.