Respuesta :

Answer: The value of equilibrium constant at -40°C is [tex]1.26\times 10^{-5}[/tex]

Explanation:

We are given:

Percent degree of dissociation = 0.456 %

Degree of dissociation, [tex]\alpha[/tex] = 0.00456

Concentration of [tex]N_2O_4[/tex], c = 0.15 M

The given chemical equation follows:

                       [tex]N_2O_4\rightleftharpoons 2NO_2[/tex]

Initial:                c             -

At Eqllm:         [tex]c-c\alpha[/tex]      [tex]2c\alpha[/tex]

So, equilibrium concentration of [tex]N_2O_4=c-c\alpha =[0.15-(0.15\times 0.00456)]=0.1493M[/tex]

Equilibrium concentration of [tex]NO_2=2c\alpha =[2\times 0.15\times 0.00456]=0.00137M[/tex]

The expression of [tex]K_{eq}[/tex] for above equation follows:

[tex]K_{eq}=\frac{[NO_2]^2}{[N_2O_4]}[/tex]

Putting values in above equation, we get:

[tex]K_{eq}=\frac{(0.00137)^2}{0.1493}\\\\K_{eq}=1.26\times 10^{-5}[/tex]

Hence, the value of equilibrium constant at -40°C is [tex]1.26\times 10^{-5}[/tex]