The coagulation of 200 mL of a positive colloid took place when 0

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 Multiple Choice QuestionsMultiple Choice Questions

181.

Gasoline is

  • C17H36 to C21H50

  • C7H24 to C14H34

  • C7H16 to C10H22

  • C3H8 to C6H14


182.

A emulsifier is a substance which :

  • stabilises the emulsion

  • homogenises the emulsion

  • coagulates the emulsion

  • accelerates the dispersion of liquid in liquid


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183.

The coagulation of 200 mL of a positive colloid took place when 0.73 g HCl was added to it without changing the volume much. The flocculation value of HCl for the colloid is

  • 100

  • 36.5

  • 0.365

  • 150


A.

100

200 mL of the solution required = 0.73 g HCl

i.e. 0.7336.5 = 0.02 mol = 20 mmol

 1000mL (1L) of the solution will require

20200×1000 = 100 mmol

Thus, the flocculation value of HCl for the colloid is 100.


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184.

Paints and hair creams are respectively

  • sol and emulsion

  • aerosol and foam

  • emulsion and sol

  • foam and gel.


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185.

Extent of adsorption of adsorbate from solution phase increases with :

  • increase in amount of adsorbate in solution

  • decrease in surface area of adsorbent

  • increase irtemperature of solution

  • decrease in amount of adsorbate in solution


186.

Which ofthe following is a negatively charged sol ?

  • Sol of charcoal

  • Haemoglobin

  • TiO2 sol

  • Basic dye stuffs


187.

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

  • dehydrating agent and catalyst

  • dehydrating agent

  • hydrolysing agent

  • catalyst


188.

Purification of colloids is done by

  • dialysis

  • peptisation

  • electrophoresis

  • coagulation.


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189.

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.


190.

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.


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