The concentration of the lactate is computed by:
Lactic acid ⇒ H+ + Lactate
pKa = 3.86
Ka = 1.38 x 10^-4 would be equal to [H+] [lactate] / [lactic acid]
HCl ⇒ H+ + Cl-
[H+] = 0.08
Lactic acid = 0.10 M
1.38 x10^-4 would be equal to 0.08 [Lactate] / 0.10
Lactate = 0.10(1.38 x 10^-4/ 0.08
Lactate = 1.73 x 10^-4
