What is the pH and pOH of 6.5 g of sodium hydroxide in 650 mL of water?

1 Answer
Feb 11, 2017

Answer:

#pH+pOH=14# in aqueous solution.

Explanation:

And since, #pOH=-log_10[HO^-]#, all we have to do is calculate the concentration of #HO^-#.

#[HO^-]=((6.5*g)/(40.00*g*mol^-1))/(650xx10^-3*L)=0.25*mol*L^-1#

So #pOH=-log_10(0.25)=-(-0.60)=0.60#

And #pH=13.4#

Spare a thought for the students who did these calculations in the days before electronic calculators. Some 30-40 years ago, students of mathematics, and physics, and chemistry, would routinely use logarithmic tables for these calculations.