Freundlich adsorption isotherm equation:
mx=kpn1where
mx= mass of gas adsorbed per unit mass of adsorbent, p= equilibrium pressure,
k and
n= empirical constants,
n>1.Or, taking logarithms,
logmx=logk+n1logpOption A:
mx=kpn1(n>1)Correct.
Option B:
Extent of adsorption of gas is more at high temperature than at low temperature.
Adsorption is an exothermic process.
Hence, increasing temperature decreases adsorption (Le Chatelier's principle).
Incorrect statement.
Option C:
n1 represents the slope of the isotherm (in log-log plot)
Since
logmx=logk+n1logp,
Correct.
Option D:
logmx=logk+n1logp holds good over a limited range of pressures.
At very high or very low pressures, Freundlich isotherm deviates.
Correct.
Final Answer:
Option B - Extent of adsorption of gas is more at high temperature than at low temperature - is not correct about Freundlich adsorption isotherm.