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

127.

Which of the following will be most effective in the coagulation of Fe(OH)₃ sol ?

• KCN

• BaCl₂

• NaCl

• Mg₃(PO₄)₂

Tyndall effect shown by colloids is due to :

• scattering of light by the particles

• movements of particles

• reflection of light by the particles

• coagulation of particles

Alum is added to muddy water because :

• it acts as disinfectant

• it results in coagulation of clay and sand

• clay is soluble in alum, hence removes it

• it makes water alkaline, which is good for health

Active charcoal is a good catalyst because :

• made up of carbon atoms

• is very reactive

• has more adsorption power

• has inert nature toward reagent