An aqueous solution of potash alum gives :

• two types of ions

• only one type of ion

• four types of ions

• three types of ions

372.

The formation of SO₃ takes place according to the following reaction :

2SO₂ + O₂ $\rightleftharpoons$ 2SO₃; $∆\mathrm{H}$ = -45.2 kcal

The formation of SO₃ is favoured by:

• increase in temperature

• removal of oxygen

• increase of volume

• increase of pressure

The process which is responsible for the formation of delta at a place where rivers meets the sea is

• Coagulation

• Colloid formation

• peptisation

• emulsification

A precipitate is changed to colloidal solution by the following process :

• dialysis

• ultrfiltation

• peptization

• electrophoresis

The movement of colloidal particles towards their respective electrodes in the presence of an electric field is known as :

• electrolysis

• Brownian movement

• dialysis

• electrophoresis

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

• High temperature

• High pressure

• Higher crtical temperature of adsorbate

• low temperature

Which of the following acts as protective colloid?

• silica gel

• gelatin

• sodium acetate

• none of these

Which of the following is the best protective colloid?

• Gelatin (Gold No. 0.005)

• Gum arabic (Gold No. 0.15)

• Egg albumin (Gold No. 0.08)

• None of the above

An example of dispersion of a liquid in a gas is :

• milk

• vegetable

• foam

• mist

Hydrogenation of vegetable oils in presence of finely divided nickel as catalyst.The reaction is

• enzyme catalysed reaction

• homogeneous catalysis

• heterogeneous catalysis

• liquid catalysed reaction