MolSynapsequestion bank

MolSynapse / Question bank / Surface Chemistry / Adsorption: physisorption vs chemisorption, Freundlich and Langmuir isotherms

JEE Advanced levelSingle correct optionDifficulty 3 of 3sc042

For a Freundlich isotherm $x / m = k p^{1/ n}$ with $0 < 1/ n < 1$ , the plot of $x / m$ against $p$ is:

Aa straight line through the origin
Ba curve that rises with increasing slope (convex upward)
Ca horizontal line parallel to the pressure axis
Da curve through the origin that keeps rising but with decreasing slope

Answer: D

For

0 < 1/ n < 1

,

p^{1/ n}

is concave:

x / m

increases but

d (x / m) / d p = (k / n) p^{1/ n - 1}

falls with

p

. It passes through the origin since

0^{1/ n} = 0

. The straight line is the case

1/ n = 1

and the horizontal line is

1/ n = 0

.

Practice Surface Chemistry More on Adsorption: physisorption vs chemisorption, Freundlich and Langmuir isotherms

Previous questionNext question

More questions on Adsorption: physisorption vs chemisorption, Freundlich and Langmuir isotherms