Nitric oxide reacts with chlorine gas according to the following reaction:
2NO(g)+Cl2(g)?2NOCl(g)
Kp=0.27 at 700 K
A reaction mixture initially contains equal partial pressures of NO and Cl2. At equilibrium, the partial pressure of NOCl was measured to be 110 torr. What were the initial partial pressures of NO and Cl2?

The initial partial pressures of and are 134 torr each.

Explanation:

The given balanced equilibrium reaction is,

Initial pressure             x          x                 0

At eqm. conc.        (x-2y)       (x-y)             2y

The expression for equilibrium constant for this reaction will be,

we are given : 2 y= 110 torr

y = 55 torr

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

Thus the initial partial pressures of and are 134 torr each