J.R. S. answered 11/16/22
Ph.D. University Professor with 10+ years Tutoring Experience
Potassium hydrogen phthalate (KHP) = C8H5KO4
Molar mass = 204 g / mol
Note that KHP has ONE ionizable hydrogen
NaOH + C8H5KO4 ==> C8H4KNaO4 + H2O
moles NaOH present = 50 ml x 1 L / 1000 ml x 0.101 mol / L = 0.00505 moles NaOH
moles KHP needed = 0.00505 mols NaOH x 1 mol KHP / mol NaOH = 0.00505 mols KHP needed
grams KHP needed = 0.00505 mols KHP x 204 g / mol = 1.03 g KHP required