Given an aqueous solution in which the #[H^+]=5.0*10^-3# #M#, what is the molar hydroxide ion concentration?

1 Answer
Feb 20, 2017

Answer:

#[HO^-]=10^(-11.7)=2.0xx10^-12*mol*L^-1#

Explanation:

The easiest way to approach this problem is to use logarithms, and use the relationship:

#pH + pOH=14#

This is specified for aqueous solution under standard conditions.

So #[H_3O^+]=5xx10^-3*mol*L^-1#, and thus,

#pH=-log_10(5xx10^-3)=2.30#

And thus #pOH=11.70#,

and thus #[HO^-]=10^(-11.7)=2.0xx10^-12*mol*L^-1#