The pH of an aqueous solution is 4.32. What is the [OH-]?

2.10 x 10^-10 M. Ans

pH + pOH = 14

Where, pOH is the power of hydroxide ion concentration and pH is the power of concetration of the H + ion.

Now, pOH = 14 - 4.32

= 9.68

Now, the concentration of [H+] is 10-7 M, then pH is 7 and for [OH-] = 10-7 M, the pOH is also 7.

Now, pOH = - log[OH-]

[OH-] = 10^ - pOH

= 10^-9.68

= 2.10 x 10^-10 M