Paper: CSIR-NET June 2016 · Subject: Physical Chemistry · Chapter: Surface Chemistry · Topic: Surface Chemistry – General · Marks: 2 · Difficulty: Hard
Adsorbtion isotherm of three gases $\mathrm{A}, \mathrm{B}, \mathrm{C}$ are shown in the following figure, where $\theta$ is the percentage of surface coverage. The correct order of the extent of adsorbtion of three gases is
(a)A $>$ B $>$ C
(b)B $>$ A $>$ C
(c)$\mathrm{C}>\mathrm{A}>\mathrm{B}$
(d)C $>$ B $>$ A
Answer
Answer: D ✓ checked by 4AB · confidence medium
Explanation
Langmuir: 1/θ = 1 + 1/(KP), so the slope of 1/θ vs 1/P is 1/K. The smallest slope (C) means the largest K and the strongest adsorption. C > B > A (d).