Question

What is the pH of a 1 M `CH_(3)COOH` a solution `K_(a)` of acetic acid `= 1.8 xx 10^(-5) K = 10^(-14) mol^(2) "litre"^(-2)`
A. 9.4
B. 4.8
C. 3.6
D. 2.4

Answer 1

Correct Answer - A
`CH_(3)COO^(-) + H_(2)O hArr CH_(3)COOH + OH^(-)`
`:. [OH^(-)] = c xx h`
`h = sqrt((K_(w))/(K_(a)) xx C) = sqrt((10^(-14))/(1.8 xx 10^(-5)) xx 1) = 2.35 xx 10^(-5)`
`:. pOH = 4.62 , pH = 9.38 ~~ 9.4`.