2NOCl(g) ↔ 2NO(g) + Cl2(g) with K = 1.6 x10–5. In an experiment, 1.00 mole of pure NOCl and 1.00 mole of pure Cl2 are placed in a 1.00-L container. If x moles of NOCl react, what is the equilibrium concentration of NO?

Respuesta :

Answer: [tex]3.8\times 10^{-3}M[/tex]

Explanation:

Moles of  [tex]NOCl[/tex] = 1 mole

Moles of  [tex]Cl_2[/tex] = 1 mole

Volume of solution = 1 L

Initial concentration of [tex]NOCl[/tex] = 1 M

Initial concentration of [tex]Cl_2[/tex] = 1 M

The given balanced equilibrium reaction is,

                  [tex]2NOCl(g)\rightleftharpoons 2NO(g)+Cl_2(g)[/tex]

Initial conc.          1 M                      0M          1 M

At eqm. conc.     (1-2x) M              (2x) M       (1+x) M

The expression for equilibrium constant for this reaction will be,

[tex]K_c=\frac{[NO]^2[Cl_2]}{[NOCl]^2}[/tex]

The [tex]K_c[/tex]= [tex]1.6\times 10^{-5}}[/tex]

Now put all the given values in this expression, we get :

[tex]{1.6\times 10^{-5}}=\frac{(2x)^2\times (1+x)}{(1-2x)^2}[/tex]

By solving the term 'x', we get :

[tex]x=0.0019[/tex]

Concentration of [tex]NO[/tex] at equilibrium= (2x) M  =  [tex]2\times 0.0019=3.8\times 10^{-3}M[/tex]