At equilibrium, the concentration of CH3COOH is 2.0 × 10–1 M, the concentration of CH3COO– is 1.9 × 10–3 M, and the concentration of H3O+ is 1.9 × 10–3 M. What is the value of Keq for this reaction?

Respuesta :

Acetic acid (CH3COOH) reacts with water to form the acetate ion and the hydronium ion:



At equilibrium, the concentration of CH3COOH is 2.0 × 10–1 M, the concentration of CH3COO– is 
1.9 × 10–3 M, and the concentration of H3O+ is 1.9 × 10–3 M. What is the value of Keq for this reaction?
1.8 * 10^-5

Answer:[tex]1.8\times 10^{-5}[/tex]

Explanation:

Concentration of [tex]CH_3COOH[/tex] = [tex]2.0\times 10^{-1}[/tex]

Concentration of [tex]CH_3COO^-[/tex] = [tex]1.9\times 10^{-3}[/tex]

Concentration of [tex]H_3O^+[/tex] = [tex]1.9\times 10^{-3}[/tex]

The balanced equilibrium reaction will be,

[tex]CH_3COOH+H_2O\rightleftharpoons CH_3COO^-+H_3O^+[/tex]

The expression for equilibrium reaction will be,

[tex]K=\frac{[H_3O^+]\times [CH_3COO^-]}{[CH_3COOH]}[/tex]

Now put all the given values in this expression

[tex]K=\frac{(1.9\times 10^{-3})\times (1.9\times 10^{-3})}{(2.0\times 10^{-1})}[/tex]

[tex]K=1.8\times 10^{-5}[/tex]

Therefore, the value of Keq for this reaction is [tex]1.8\times 10^{-5}[/tex]