SURFACE CHEMISTRY

Front

Which process does not occur at the interface of phases? Options: crystallisation, heterogenous catalysis, homogeneous catalysis, corrosion

Back

homogeneous catalysis

Front

At the equilibrium position in the process of adsorption, what is the relationship between ΔH and TΔS?

Back

ΔH = TΔS

Front

Which of the following interface cannot be obtained? liquid-liquid, solid-liquid, liquid-gas, gas-gas

Back

gas-gas

Front

Sorption

Back

both absorption and adsorption

Front

Extent of physisorption of a gas increases with ___________. Options: increase in temperature, decrease in temperature, decrease in surface area of adsorbent, decrease in strength of van der Waals forces.

Back

decrease in temperature.

Front

Extent of adsorption of adsorbate from solution phase increases with ________.

Back

increase in amount of adsorbate in solution.

Front

Which one of the following is not applicable to the phenomenon of adsorption? ΔH > 0, ΔG < 0, ΔS < 0, ΔH < 0

Back

ΔH > 0

Front

Which of the following is not a favourable condition for physical adsorption?

• high pressure
• negative ΔH
• higher critical temperature of adsorbate
• high temperature

Back

high temperature

Front

Physical adsorption of a gaseous species may change to chemical adsorption with:

• decrease in temperature
• increase in temperature
• increase in surface area of adsorbent
• decrease in surface area of adsorbent

Back

increase in temperature

Front

Why does adsorbent in physisorption not show specificity for any particular gas?

Back

involved van der Waals forces are universal.