surface chemistry

Which of the following interface cannot be obtained?

• liquid-liquid

• solid-liquid

• liquid-gas

• gas-gas

The term ‘sorption’ stands for ____________.

• absorption

• adsorption

• both absorption and adsorption

• desorption

Extent of physisorption of a gas increases with ___________.

• increase in temperature.

• decrease in temperature.

• decrease in surface area of adsorbent.

• decrease in strength of van der Waals forces.

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

• high pressure

• negative ΔH

• higher critical temperature of adsorbate

• high temperature

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

Which of the following is an example of absorption?

• Water on silica gel

• Water on calcium chloride

• Hydrogen on finely divided nickel

• Oxygen on metal surface

At high concentration of soap in water, soap behaves as ____________.

• molecular colloid

• associated colloid

• macromolecular colloid

• lyophilic colloid

Which of the following will show Tyndall effect?

• Aqueous solution of soap below critical micelle concentration.

• Aqueous solution of soap above critical micelle concentration.

• Aqueous solution of sodium chloride.

• Aqueous solution of sugar.

Freshly prepared precipitate sometimes gets converted to colloidal solution by ___________.

• coagulation

• electrolysis

• diffusion

• peptisation

Which of the following electrolytes will have maximum coagulating value for AgI/Ag+ sol?

• Na2S

• Na3PO4

• Na2SO4

• NaCl