Equilibrium Question 800
Question: At a certain temperature the dissociation constants of formic acid and acetic acid are $ 1.8\times {10^{-4}} $ and $ 1.8\times {10^{-6}} $ 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
Options:
A) 0.001 M
B) 0.01 M
C) 0.1M
D) 0.0001 M
Show Answer
Answer:
Correct Answer: B
Solution:
$ [{H^{+}}]=\sqrt{C\times K_{a}}=\sqrt{0.001\times 1.8\times {10^{-4}}} $ for formic acid $ [{H^{+}}]=\sqrt{C_2\times 1.8\times {10^{-5}}} $ for acetic acid Equating and solving, $ C_2=0.01,M. $
