A 0.010 M solution of maleic acid, a monoprotic organic acid, is 14 % ionised. What is Ka for maleic acid?

Question

A 0.010 M solution of maleic acid, a monoprotic organic acid, is 14 % ionised. What is Ka for maleic acid? (A) 2.3 × 10-3 (B) 2.3 × 10-4 (C) 2.0 × 10-4 (D) 2.0 × 10-6

Tardigrade Admin · Accepted Answer

Ka=C α2 /(1 / α) where, C= concentration =0.01 M α= degree of dissociation =14 %=0.14 Ka=0.01 ×(0.14)2 /(1-0.14) =(1.96 × 10-4/0.86) =2.27 × 10-4 ≈ 2.3 × 10-4

Q. A $0.010 M$ solution of maleic acid, a monoprotic organic acid, is $14%$ ionised. What is $K_{a}$ for maleic acid?

$2.3 \times 1 0^{- 3}$

$2.3 \times 1 0^{- 4}$

$2.0 \times 1 0^{- 4}$

$2.0 \times 1 0^{- 6}$

$K_{a} = C α^{2} / (1/ α)$
where, $C =$ concentration $= 0.01 M$
$α =$ degree of dissociation $= 14% = 0.14$
$K_{a} = 0.01 \times (0.14)^{2} / (1 - 0.14)$
$= \frac{1.96 \times 1 0 ^{- 4}}{0.86}$
$= 2.27 \times 1 0^{- 4} \approx 2.3 \times 1 0^{- 4}$

Q. A 0.010M solution of maleic acid, a monoprotic organic acid, is 14% ionised. What is Ka​ for maleic acid?

2.3×10−3

2.3×10−4

2.0×10−4

2.0×10−6