At a certain temperature, the dissociation constants of formic acid and acetic acid are 1.8× 10-4 and 1.8× 10-5 respectively. The concentration of acetic acid solution in which the hydrogen ion has the same concentration as in 0.001 M formic acid solution is equal to

Question

At a certain temperature, the dissociation constants of formic acid and acetic acid are 1.8× 10-4 and 1.8× 10-5 respectively. The concentration of acetic acid solution in which the hydrogen ion has the same concentration as in 0.001 M formic acid solution is equal to (A) 0.01 M (B) 0.001 M (C) 0.1 M (D) 0.0001 M

Tardigrade Admin · Accepted Answer

[H+]=Ka.C Given, [H+]HCOOH=[H+]CH3COOH Ka.C=KaC ⇒ 1.8× 10-4× 0.001=1.8× 10-5× C ∴ C=0.01 M

Q. At a certain temperature, the dissociation constants of formic acid and acetic acid are $1.8 \times 10^{- 4}$ and $1.8 \times 10^{- 5}$ respectively. The concentration of acetic acid solution in which the hydrogen ion has the same concentration as in 0.001 M formic acid solution is equal to

0.01 M

0.001 M

0.1 M

0.0001 M

0.1010 M

$[H^{+}] = K_{a} . C$
Given, $[H^{+}]_{H COO H} = [H^{+}]_{C H_{3} COO H}$
$K_{a} . C = K_{a} C$
$\Rightarrow$ $1.8 \times 10^{- 4} \times 0.001 = 1.8 \times 10^{- 5} \times C$
$∴$ $C = 0.01 M$

Q. At a certain temperature, the dissociation constants of formic acid and acetic acid are 1.8×10−4 and 1.8×10−5 respectively. The concentration of acetic acid solution in which the hydrogen ion has the same concentration as in 0.001 M formic acid solution is equal to