Question

Methylene blue, from its aqueous solution, is adsorbed on activated charcoal at $${25^ \circ }C.$$  For this process, the correct statement is

A. The adsorption requires activation at 25°C
B. The adsorption is accompanied by a decrease in enthalpy  
C. The adsorption increases with increase of temperature
D. The adsorption is irreversible
Answer :   The adsorption is accompanied by a decrease in enthalpy
Solution :
The adsorption of methylene blue on activated charcoal is an example of physiosorption which is exothermic, multilayer and does not have energy barrier.

Releted MCQ Question on
Physical Chemistry >> Surface Chemistry

Releted Question 1

Rate of physiorption increases with

A. decrease in temperature
B. increase in temperature
C. decrease in pressure
D. decrease in surface area
View Answer
Releted Question 2

Adsorption of gases on solid surface is generally exothermic because

A. enthalpy is positive
B. entropy decreases
C. entropy increases
D. free energy increases
View Answer
Releted Question 3

Lyophilic sols are

A. Irreversible sols
B. They are prepared from inorganic compound
C. Coagulated by adding electrolytes
D. Self-stabilizing
View Answer
Releted Question 4

Among the following, the surfactant that will form micelles in aqueous solution at the lowest molar concentration at ambient condition is : -

A. $$C{H_3}{\left( {C{H_2}} \right)_{15}}{N^ + }{\left( {C{H_3}} \right)_3}B{r^ - }$$
B. $$C{H_3}{\left( {C{H_2}} \right)_{11}}OSO_3^ - N{a^ + }$$
C. $$C{H_3}{\left( {C{H_2}} \right)_6}CO{O^ - }N{a^ + }$$
D. $$C{H_3}{\left( {C{H_2}} \right)_{11}}{N^ + }{\left( {C{H_3}} \right)_3}B{r^ - }$$
View Answer

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Surface Chemistry

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Physical ChemistrySome Basic Concepts in ChemistryStoichiometryStates of Matter Solid, Liquid and GasAtomic StructureChemical ThermodynamicsSolutionsSolid StateSurface ChemistryChemical EquilibriumIonic EquilibriumChemical KineticsRedox ReactionElectrochemistryNuclear Chemistry
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