Question

For XY2 =XY+Y, initially 1 mole each
of XY, & Y are present in 10 lit flask at 500
mm. If the equilibrium pressure of XY is
150mm, K, is
1) 500 mm Hg 2) V500 mm Hg
3) 300 mm Hg 4) 600 mm Hg/​

Answer 1

Answer : The correct option is, (4) 600 mmHg

Explanation :

Both have same partial pressure. So,

The partial pressure of $XY_2$ = 250 mmHg

The partial pressure of $Y$ = 250 mmHg

The balanced equilibrium reaction is,

                                $XY_2\rightleftharpoons XY+Y$

Initial pressure     250        0      250

At eqm.               (250-p)     p    (250+p)

The expression of equilibrium constant $K_p$ for the reaction will be:

$K_p=\frac{(p_{XY})(p_{Y})}{(p_{XY_2})}$

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

$K_p=\frac{(250+p)(p)}{(250-p)}$

The equilibrium partial pressure of XY = p = 150 mmHg

So, $K_p=\frac{(250+150)(150)}{(250-150)}$

$K_p=600$

Therefore, the correct option is, (4) 600 mmHg