Question

A solution of sodium hydroxide is standard-
ized against potassium hydrogen phthalate
(KHP, formula weight 204.2 g/mol). From
the following data, calculate the molarity of
the NaOH solution: mass of KHP 1.894 g;
buret reading before titration 0.13 mL; buret
reading after titration 32.57 mL.
Answer in units of M.

Answer 1

moles KHP = grams/molar mass
Substitute and solve for mols.

KHP + NaOH ==> NaHP + H2O
so the reaction is 1:1 and moles KHP = moles NaOH.
Then M NaOH = moles NaOH/L NaOH.
To obtain L NaOH, you will need to subtract the final buret reading - initial buret reading and convert to L.

Answer 2

Do I use the molar mass of just KHP or with H2O as well?

Answer 3

mols of solute therefore just KHP