AIIMS 2008
- Exam
- AIIMS
- Year
- 2008
- Subject
- Chemistry
- Chapter
- Chemical Equilibrium
AIIMS 2008 · Chemistry · Chemical Equilibrium
The dissociation equilibrium of a gas A B_2 can be represented as...
The dissociation equilibrium of a gas can be represented as
The degree of dissociation is and is small compared to 1 . The expression relating the degree of dissociation with equilibrium constant and total pressure is
Options
- A(\left(2 K_p / p\right)^{1 / 2})
- B
- C
- D(\left(2 K_p / p\right)^{1 / 3}).
Correct answer
D. (\left(2 K_p / p\right)^{1 / 3}).
Step-by-step solution
\begin{aligned} & \text{ Moles at equilibrium }=2(1-x)+2 x+x \\ & =2-2 x+2 x+x=x+2 \\ & \begin{aligned} K_p & =\frac{\left[P_{A B}\right]^2\left[P_{B_2}\right]}{\left[P_{A B_2}\right]}=\frac{\left(\frac{2 x}{x+2} \times p\right)^2\left(\frac{x}{2+x} \times p\right)}{\left[\frac{2(1-x)}{x+2} \times p\right]^2} \\ & =\frac{\frac{4 x^3}{x+2} \times p}{4(1-x)^2}=\frac{4 x^2 \times p}{2} \times \frac{1}{4}\end{aligned}\end{aligned} x=\left(\frac{2 K_p}{p}\right)^{1 / 3}
(as1-x \approx 1,2+x \approx 2