Question

A solution of sodiumhydroxide (NaOH) wasstandardized against potassium hydrogenphthalate (KHP). A knownmass of KHP was titrated with
the NaOH solution until a light pink color appearedusingphenolpthalein indicator. Using the volume of NaOH requiredtoneutralize KHP and the
number of moles of KHP titrated, the concentration of theNaOHsolution was calculated.
A vinegar (acetic acid) solution of unknown concentrationwastitrated to the light pink endpoint with the standardizedNaOHsolution. The
molarity and weight\volume % of the vinegar solutionwerecalculated.
A vitamin C (ascorbic acid) tablet was dissolved in approximately50mL of distilled water and titrated with the standardizedNaOHsolution. From
the results of this titration, the mg of ascorbic acid in thetabletwas calculated.

Molecular formulas:

Potassium hydrogen phthalate: HKC8H4O4
Acetic acid: C2H4O2
Ascorbic acid: C6H8O6
Assume that all 3 acids are monoprotic acids.

Mass of KHP used forstandardization(g) 0.5548
Volume of NaOH required to neutralize KHP(mL) 13.40
Volume of vinegar sample titrated (mL) 5.00
Volume of NaOH required to neutralize vinegarin(mL) 8.53
Molecular weight of ascorbic acid(g/mol) 176.1271
Volume of NaOH required to neutralize ascorbic acid in VitaminCtablet (mL) 13.97

Calculate thefollowing


1. Calculate the amount of ascorbic acid in the Vitamin C tabletin(mg).???