The work of conc. H₂SO₄ in esterification process is as :

• dehydrating agent and catalyst

• dehydrating agent

• hydrolysing agent

• catalyst

Purification of colloids is done by

• dialysis

• peptisation

• electrophoresis

• coagulation.

443.

A colloidal solution is kept in dark and is illuminated by a beam of light then, brightness appears at the right angle of direction of light. This effect is called

• Tyndall effect

• Brownian effect

• Hardy-Schulze effect

• none of the above.

Assertion: Coagulation power of Al³⁺ is more than Na⁺.

Reason:Grealer the valency ofthe flocculating ion added, greater is its power to cause precipitation (Hardy-Schulze rule).

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Blue colour of water in sea is due to :

• refraction of blue light by impurities in sea water

• refraction of blue sky by water

• scattering of light by impurities

• All of the above

In aerosol, the dispersion medium is :

• solid

• liquid

• gas

• all of the above

A colloidal solution is kept in dark and is illuminated by a beam of light then brightness appears at the right angle of direction of light. This effect is called

• Tyndall effect

• Brownian effect

• Hardy- Schulze effect

• none of these

Hair cream is

• gel

• emulsion

• solid sol

• sol

According to Hardy schulze law, the flocculating power of an ion increases with

• decreases in size

• increase in size

• decrease in charge

• increase in charge

Butter is an example of which type of colloid?

• Solid in liquid

• Liquid in solid

• Liquid in liquid

• Gas in liquid