Surface Chemistry

Which one of the following is an example of adsorption?

• ammonia in contact with water

• anhydrous CaCl2 with water

• silica gel in contact with water vapours

• all of these

If the dispersed phase is a liquid and the dispersion medium is solid, the colloid is known as

• foam

• sol

• emulsion

• gel

Identify the shown shape selective catalyst used to convert alcohol to gasoline?

• Trpsin

• ZSM-5

• Calgon

• Zeigler-Natta catalyst

Which of the following process does not occur at the interface of phases?

• crystallisation

• heterogenous catalysis

• homogeneous catalysis

• corrosion

Which one of the following is not applicable to the phenomenon of adsorption?

• ΔH > 0

• ΔG < 0

• ΔS < 0

• ΔH < 0

In physisorption adsorbent does not show specificity for any particular gas because ______________.

• involved van der Waals forces are universal.

• gases involved behave like ideal gases.

• enthalpy of adsorption is low.

• it is a reversible process.

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

Which of the following process is responsible for the formation of delta at a place where rivers meet the sea?

• Emulsification

• Colloid formation

• Coagulation

• Peptisation