Chemical and Ionic Equilibrium 1 Question 48

50. $\mathrm{N}{2} \mathrm{O}{4}is25 %dissociatedat37^{\circ} \mathrm{C}andoneatmospherepressure.Calculate(i)K_{p}and(ii)thepercentagedissociationat0.1 \mathrm{~atm}and37^{\circ} \mathrm{C}$.

(1988,4M)

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Solution:

$$ \begin{aligned} & \mathrm{N}{2} \mathrm{O}{4} \rightleftharpoons 2 \mathrm{NO}{2} \quad \text { Total } \ & p{i}: \quad 1α2α 1α1+αp2α1+αp \ & K_{p}=\frac{4 \alpha^{2}}{1-\alpha^{2}} p=\frac{4(0.25)^{2}}{1-(0.25)^{2}}=0.26 \mathrm{~atm} \end{aligned} $$

When p=0.10 atm

$$