Question

Calculate the pH and the concentrations of all species of 0.100 M ascorbic acid solution. . Concentrations must be in molarity, M.

List your answers in the following [H₃O⁺], [H₂A], [HA^-], [A^-]

ksp 8.0E-5

Answer 1

0 As corbic and (vitamin e) is a weak di protic acid with molemlar formula C6Hg Of The dissociation of a scorbic acid can be written as, Ist dissacation, H₂C6t66 (at) f t t can t t Cotton can kas 79 405 ciation of and dissociation, HCG H60 Can Htca + Cotto 2- The second dissociation of ka₂=1.6x1012 very small almost negligible the solution appears due to Ist dissociation of as corbic acid which r releases 44 im in solution ascorbic acid is с. и 18's. ICE table He He of Car + H₂O(l) Initial, 0.10 F H₂otcam +HCG Hoor ca change, Equilibrium, 0.10nm) - bene acid the dissociation of ascorbi [#30t] [st Coltoo ЕН, С, а ос) 7.9x10-5 7.9x105 TOJo-n) = 10 ar Ja. 10x 7.9x105 * 2.8106 X103 [H3O+] = [H Co to or] =nn. and, [H₂ CG He 6] (0.1-2.81064103M = 21 = 0.0971M ika, is very Small, will be show in comparison to allo : 0.10 -* * 0.10 01 - 219106x103) M 2.810X 3 M

Now, pH = -log [Hz ot] Erlog (2.8106x103) - 25511 Now, for and dissociation of ascorbic acid, kaz = [H +] [ ColH6962] [ HCH Oe] 3) [catto- kaze IH Cu tov) Esti] * H) : 4 20"] = 48 0 6 113 > [cate or] . 16x1012 X281216+3 2.81 x 103 - 1.6x10 12 concentration of M ascorbate I lotto 02] = ion so 1.6 8 10 12 m species, eque librium concentration of every [JIA] - [ H₂ Catto 6] – 0.0971M [1304) 2.8106 x 103 m [ SHA-] = [H G H 9 ] = 2.81x103 m and [A2] = [ C H236 ] = 16x10-12