At `25^@C` and 1 atm, the partial pressure in an equilibrium mixture of `N_2O_4 (g) and NO_(2) (g) ` are 0.70 atm and 0.30 atm respectively. Calculate their partial pressure when they are at equilibrium at 9.0 atm and `25^@C?`

Explanation

For the equilibrium `underset("0.3 atm")(2NO_(2)) Leftrightarrow underset("0.7 atm")(N_2O_4)`
`K_p=(p_(N_2O_4))/(p_(NO_(2))^(2))=(0.7)/((0.3)^(2))=7.77`
Let the equilibrium pressure of `NO_2 and N_2O_4" be "p_1 and p_2` atm at 9.0 atm at the same temperature.
`K_p=(p_2)/p_1^2=7.77 ........(1)`
and `p_1+p_2=9.0 ........(2)`
Solving eqns. (1) and (2)
`p_(1)=1.01 atm`
`p_2=7.99atm`