7-b. a solution of naoh was standardized by gravimetric titration of a known quantity of the primary standard, potassium hydrogen phthalate: ao — potassium hydrogen phthalate c8 h5 o4 k, fm 204.22 ß ß co2k co3h 2 ß ß co2k co2na b the naoh was then used to fi nd the concentration of an unknown solution of h2so4: h2so4 1 2naoh s na2so4 1 2h2o (a) verify from the structure of potassium hydrogen phthalate that its formula is c8h5o4k. (b) titration of 0.824 g of potassium hydrogen phthalate required 38.314 g of naoh solution to reach the end point detected by phenolphthalein indicator. find the concentration of naoh (mol naoh/kg solution). (c) a 10.00-ml aliquot of h2so4 solution required 57.911 g of naoh solution to reach the phenolphthalein end point. find the molarity of h2so4.