What is pOHpOH of a solution prepared by adding a 15.8*mg15.8mg mass of potassium hydroxide to 11*mL11mL of solution?

1 Answer
May 9, 2017

pOH=1.60pOH=1.60

Explanation:

Now..........pOH=-log_10[HO^-]pOH=log10[HO]...........

And we have 15.8*mg15.8mg KOHKOH dissolved in 11*mL11mL of solution.

[HO^-]=((15.8xx10^-3*g)/(56.11*g*mol^-1))/(11*mLxx10^-3*mL*L^-1)[HO]=15.8×103g56.11gmol111mL×103mLL1

=2.56xx10^-2*mol*L^-1=2.56×102molL1.

But by definition, pOH=-log_10(2.56xx10^-2)=1.60pOH=log10(2.56×102)=1.60

What is pHpH of this solution? You should be able to answer immediately. Why? Because in aqueous solution, pH+pOH=14pH+pOH=14.

Also see this [old problem here for more treatment.](https://socratic.org/questions/ph-value-definition)