TABLE 16.3 Acid-Dissociation Constants of Some Common Polyprotic Acids Name Formula K1 K2 Ascorbic H2CH¿O6 8.0 x 10-5 1.6 x 10-12 Carbonic Н.СО, 4.3 x 10-7 5.6 x 10-1" Citric H;C,H5O7 7.4 x 104 1.7 x 10-5 4.0 x 107 Охalic HOOC-COOH 5.9 x 10-2 6.4 x 10-5 Phosphoric Н,РО, 7.5 x 10-3 6.2 x 10-8 4.2 x 10-13 Sulfurous H,SO, 1.7 x 10 2 6.4 x 108 Sulfuric H2SO4 Large 1.2 x 10-2 Tartaric С-Н.О,(СООН)2 1.0 x 10- 4.6 x 10-5

Tartaric acid is found in many fruits, including grapes, and is
partially responsible for the dry texture of certain wines. Calculate
the pH and the tartrate ion (C₄H₄O₆^2-) concentration
for a 0.250 M solution of tartaric acid, for which the acid-dissociation
constants are listed in Table . Did you have to make
any approximations or assumptions in your calculation?