Question

Select all that apply.

Consider this system: CH3COOH(aq) H+(aq) + CH3COO- Ka = 1.8 x 10-5
What will happen to the equilibrium as OH- ions are added?

A) H+ will combine with OH- to form water.
B) [CH3COOH] will increase.
C) The acid will dissociate to supply more H+.
D) The reaction will move to the right.
E) The reaction will move to the left.

Answer 1

Answer : The correct options are, (A), (C) and (D)

Explanation :

Le-Chatelier's principle : It states that if any change in the variables of the reaction, then the equilibrium will shift in that direction where the effect will be minimum.

The balanced equilibrium reaction will be,

`CH_3COOH(aq)\rightleftharpoons H^+(aq)+CH_3COO^-`

As the concentration of
`H^+` are decreased, the equilibrium will shift in a direction where concentration of
`H^+` is increasing and thus the dissociation of acid will increase to supply more of
`H^` ions. During this process the reaction will move to the right direction.

In the given equilibrium reaction when the
`OH^-` are added then the
`H^+` ion will combine with
`OH^-` ion to form water.

Hence, the correct options are, (A), (C) and (D)

Answer 2

Consider this system: CH3COOH(aq) H+(aq) + CH3COO- Ka = 1.8 x 10-5
The equilibrium as OH- ions are added;

A) H+ will combine with OH- to form water.

C) The acid will dissociate to supply more H+.
D) The reaction will move to the right.