Gold number is associated with from Chemistry Surface Chemistry

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 Multiple Choice QuestionsMultiple Choice Questions

171.

Cow milk, an example of natural emulsion, is stabilised by

  • fat

  • water

  • casein

  • Mg2+ ions


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172.

Gold number is associated with

  • amount of gold

  • protective colloids

  • purple of cassius

  • electrophoresis


A.

amount of gold

The protective power of a colloid is expressed as gold number. Gold number is defined as the minimum amount of lyophilic colloid in milligrams which prevents the flocculation of 10 ml gold sol by the addition of 1 ml of 10% NaCl solution.


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173.

Which one of the following forms micelles in aqueous solution above certain concentration?

  • Urea

  • Dodecyl trimethyl ammonium chloride

  • Pyridinium chloride

  • Glucose


174.

Migration of colloidal particles towards the oppositely charged electrode is called:

  • Electrosmosis

  • Electrophoresis

  • Coagulation

  • Electrodispersion


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175.

The variation of adsorption of N, on charcoal with pressure at different constant temperature can be represented by :

The correct increasing order of temperature
T1 , T2 and T3 is :

  • T1 < T2 < T3

  • T2 < T3 < T1

  • T3 < T2 < T1

  • T2 < T1 < T3


176.

Which of the following statement is not correct?

  • Adsorption energy for chemical adsorption is generally greater than that of physical adsorption

  • Physical adsorption is due to van der Waal forces

  • Physical adsorption decreases at high temperature and low pressure

  • Physical adsorption is irreversible


177.

Solvent loving colloids are known as

  • hydrophobic

  • lyophilic

  • hydrophilic

  • none of these


178.

Freundlich adsorption isotherm gives a straight line on plotting:

  • xm vs p

  • log xm vs p

  • log xm vs log p

  • xm vs 1p


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179.

Arsenic sulphide sol is prepared by passing H2S through arsenic oxide solution. The charge developed on the particles is due to adsorption of :

  • H+

  • S2-

  • OH-

  • O2-


180.

Which one of the following colloidal solution is positive sol?

  • Gelatin in strongly acidic solution

  • Smoke

  • Dlay soil

  • Blood


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