Question

Lactic acid (ch3ch(oh)cooh) has one acidic hydrogen. a 0.10 m solution of lactic acid has a ph of 2.44. calculate ka.

Answer 1

The answer is : Ka=0.000137

HA -> H+ + A-

0.10 x x

0.10-x +x +x

[H+]= 10^-2.44 = 0.00363

x= 0.00363

(0.00363)(0.00363)/(0.10-0.00363) = 0.000137

Ka=0.000137