KHP is a monoprotic acid with a molecular formula of KHC8H4O4 (MW = 204.2215 g/mol). In order to titrate a sample of KHP, a stock solution of NaOH was standardized by titration with 0.1453 M HCl. The endpoint of the HCl/NaOH titration was reached when 18.23 ml of HCl was added to 10.00 ml of NaOH. If 18.85 mL of NaOH was then required to reach an equivalence point with 1.564 g of an impure KHP sample, what is the % composition of KHP in the impure sample?