Accumulation of lactic acid (HC3H5O3), a monobasic acid in tissues leads to pain and a feeling of fatigue. In a 0.10 M aqueous solution, lactic acid is 3.7 % dissociates. The value of dissociation constant, Ka, for this acid will be :

Question

Accumulation of lactic acid (HC3H5O3), a monobasic acid in tissues leads to pain and a feeling of fatigue. In a 0.10 M aqueous solution, lactic acid is 3.7 % dissociates. The value of dissociation constant, Ka, for this acid will be : (A) 1.4 × 10-5 (B) 1.4 × 10-4 (C) 3.7 × 10-4 (D) 2.8 × 10-4

Tardigrade Admin · Accepted Answer

Degree of dissociation, α=3.7=0.037 Ka=α2 C=(0.037)2 × 0.10 =1.369 × 10-4 ≈ 1.4 × 10-4

Q. Accumulation of lactic acid $(H C_{3} H_{5} O_{3}$ ), a monobasic acid in tissues leads to pain and a feeling of fatigue. In a $0.10 M$ aqueous solution, lactic acid is $3.7%$ dissociates. The value of dissociation constant, $K_{a}$ , for this acid will be :

$1.4 \times 1 0^{- 5}$

$1.4 \times 1 0^{- 4}$

$3.7 \times 1 0^{- 4}$

$2.8 \times 1 0^{- 4}$

Degree of dissociation, $\alpha=3.7=0.037$
$K_{a}=\alpha^{2} C=(0.037)^{2} \times 0.10 $
$=1.369 \times 10^{-4} \approx 1.4 \times 10^{-4}$

Q. Accumulation of lactic acid (HC3​H5​O3​), a monobasic acid in tissues leads to pain and a feeling of fatigue. In a 0.10M aqueous solution, lactic acid is 3.7% dissociates. The value of dissociation constant, Ka​, for this acid will be :

1.4×10−5

1.4×10−4

3.7×10−4

2.8×10−4