Question

Ochem

Tartaric acid, is a crystalline precipitate that often forms on the surface of the cork that is in contact with wine in wine bottles. The pKa of tartaric acid is approximately 3. At pH 7, what will be the approximate ratio of the L-tartaric acid to the conjugate base (B) (ratio of L-tartaric acid : B)? The structures and the dissociation equation are given below OH O OH O O+HKa103 O OH L-tartaric acid O OH O 1:1 ○ 1:100 O1:1,000 1:10,000 O 1:100,000

Answer 1

PH = 7 as PH = -log [H^+] = 7 so log [H^+] = -7 [H^+] = 10^-7 using K_a = 10^-3 K_a = [conjugate base] [H^+]/[L - tartaric acid] = 10^-3 [L - tartaric acid]/ [conjugate base] = [H^+]/10^-3 = 10^-7/10^-3 = 10^-4 = 1/10000 so, 1: 10,000 4^th option