Question

A flask containing $0.5$ atm pressure of $A_2\left(g\right)$, some solid $AB$ added into flask which undergoes dissociation according to :
$2AB\left(s\right)\rightleftharpoons A_2\left(g\right)+B_2\left(g\right)$
$K_p=0.06{atm}^2$. The total pressure (in atm) at equilibrium is :

• A. $0.70$
• B. $0.6$
• C. $0.10$
• D. none of these

Answer 1

The correct option is A $0.70$

For reaction:
$2AB\left(s\right)\rightleftharpoons A_2\left(g\right)+B_2\left(g\right)$
t=0 - 0.5 -
At eqm - $0.5+x$ $x$

And $K_p=0.06{atm}^2=(0.5+x)x;\Rightarrow x=\mathrm{0.1.}$

So, total pressure at eqm is $0.5+0.1+0.1=0.7atm.$