Chapter 16, Problem 105FP

Maleic acid is a carbon-hydrogen-oxygen compound used in dyeing and finishing fabrics and as a preservative of oils and fats in a combustion analysis, a 1.054 g sample of maleic acid yields 1.599 g CO_: and 0.327 g H₂O. In a freezing-point depression experiment, a 0.615 g sample of maleic acid dissolved in 25 10 g of glacial acetic acid. CH₂COOH(l) (which has the freezing-point depression constant K= 3.90 'Cm-1 and in which maleic acid does not ionize) lowers me freezing point by In a titration experiment, a 0 4250 g sample of maleic acid is dissolved in water and requires 34 03 mL of 0 2152 M KOH for its complete neutralization The pH of a 0 215 g sample of malek acid dissolved in 50 00 mL of aqueous solution is found to be 1 80
(a) Determine the empirical and molecular formulas at maleic bckJ. [Hint: Which expenment(s) provide the necessary data⁷}
(b) Use the results of part (a) and the titration data to rewrite the molecular formula to reflect the number of ionizable H atoms in the molecule.
(c) Given that the ionizable H atom(s) is(are) associated with the carboxyl groupisj write the plausible condensed structural formula of maleic acid.
(d) Determine the ionization c onstant(s) of maleic acid If the data suppSed are insuffic lent, indie ate what additional data would be needed
(e) Calculate the expected pH of a 0 0500 M aqueous solution of maleic acid, indicate any assumptions required in this calculationb