Question

the titration of an impure sample of KHP found that 36.0 ml of 1.00M NaOH was required to react completely with 0.765g of sample. what is the percentage of KHP in this sample?

Answer 1

Balanced equation for reaction between KHP( KHC8H4O4 )and NaOH is

KHC8H4O4 + NaOH ---------> KNaC8H4O4 + H2O

It seems 0.1 M NaOH

moles of NaOH = Molarity x volume in Litres

                           = 0.1 M x 0.036 L

= 0.0036 mol

= 0.0036 moles KHP

Mass of KHP = moles of KHP x Molar mass of KHP

                     = 0.0036 mol x 204.22 g/mol

                     = 0.735 g

Given that mass of impure KHP sample = 0.765 g

Therefore,

% KHP = (0.735 g/ 0.765 g) x 100

= 96.07 %