Potassium hydrogen phthalate is a solid monoprotic acid freq

Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory to standardize strong base solutions. It has the unwieldy formula of KHC₈H₄O₄. This is often written in shorthand notation as KHP.

How many grams of KHP are needed to exactly neutralize 22.1 mL of a 0.331 M sodium hydroxide solution ?

? grams KHC₈H₄O₄

Solution

volume of NaOH = 22.1 mL

concentration = 0.331 M

moles of NaOH = 22.1 x 0.331 / 1000

                         = 7.32 x 10^-3 mol

KHP    +    NaOH    ------------------> NaKP   + H2O

moles of KHP   =   moles of NaOH

moles of KHP = 7.32 x 10^-3 mol

mass of KHP = moles x molar mass

                   = 7.32 x 10^-3 x 204.22

mass of KHP = 1.49 g