Question

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. What volume of a 0.458 M sodium hydroxide solution is needed to exactly neutralize 2.97 grams of KHP ?

Answer 1

32 mL

Explanation:

Since we know what is the amount of KHP which will be neutralized, we need to calculate the number of moles of KHP present and from there it will be easy to determine the moles required since it is a one to one reaction ( monoprotic acid).

Once we have this number of moles of NaOH we can calculate the volume of solution of concentration 0.458 molar needed.

Mol Weight KHP = 204.22 g/mol

n KHP = 2.97 g x 1 mol/204.22 g/mol

n KHP = 0.0145 mol

0.0145 mol KHP x 1 mol NaOH/ 1 mol KHP = 0.0145 mol NaOH

Vol NaOH

=0.0145 moll NaOH x ( 1L/0.458 mol NaOH ) (from to the formula M = # mol/V the # mol = M x V)

= 0.032 L = 32 mL