Question

Consider the reaction between NO and Cl2 to form NOCl: 2NO(g)+Cl2(g)⇌2NOCl(g) A reaction mixture at a certain temperature initially contains only [NO]= 0.57 M and [Cl2]= 0.66. After the reaction comes to equilibrium, the concentration of NOCl is 0.27 M .

Answer 1

Answer: Value of the equilibrium constant is 1.5

Explanation:

Initial concentration of $NO$  = 0.57 M

Initial concentration of $Cl_2$  = 0.66 M

Equilibrium concentration of $NOCl$  = 0.27 M

The given balanced equilibrium reaction is,

               $2NO(g)+Cl_2(g)\rightleftharpoons 2NOCl(g)$

Initial conc.       0.57 M    0.66      0

At eqm. conc.   (0.57-2x)M (0.66-x)M   (2x)M

The expression for equilibrium constant for this reaction will be,

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

$K_c=\frac{(2x)^2}{(0.57-2x)^2\times (0.66-x)}$

we are given : 2x= 0.27 M

x = 0.135 M

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

$K_c=\frac{(0.27)^2}{(0.57-0.27)^2\times (0.66-0.135)}$

$K_c=1.5$

Thus the value of the equilibrium constant is 1.5