The size of colloidal particles is in between from Chemistry Sur

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 Multiple Choice QuestionsMultiple Choice Questions

61.

Colloidal solution of gold is in different colours like red, purple, blue and golden because of

  • variable oxidation states of gold

  • size difference in the particles of gold

  • presence of impurities

  • difference in the concentration of gold particles


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62.

The size of colloidal particles is in between

  • 10-7 - 10-9 cm

  • 10-9 - 10-11 cm

  • 10-5 - 10-7 cm

  • 10-2 - 10-3 cm


C.

10-5 - 10-7 cm

Size of colloidal particles is in the following order- 

between 10-5 cm to 10-7 cm

between 10-9 m to 10-7 m

between 1 nm to 100 nm

between 10 Å to 1000 Å


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63.

The stability of lyophilic colloids is due to which of the following?

  • Charge on their particles

  • Large size of their particles

  • Smaller size of their particles

  • A layer of medium of dispersion on their particles


64.

Milk is

  • fat dispersed in water

  • water dispersed in fat

  • water dispersed in oil

  • fat dispersed in fat


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65.

In chemical adsorption, how many layers are adsorbed?

  • One

  • Two

  • Multi

  • Zero


66.

What is the role of a catalyst in a catalysed reaction?

  • Lowers the activation energy

  • Increases the activation energy

  • Affects the free energy change

  • Affects the enthalpy change


67.

For coagulating As2S3 colloidal solution which of the following will have the lowest coagulation value?

  • NaCl

  • KCl

  • BaCl2

  • AlCl3


68.

Which of the following chemical reactions is homogeneous catalytic reaction?

  • N2(g) + 3H2(g) Fe 2NH3(g)

  • 2SO2(g) + O2(g) NO 2SO3 (g)

  • CO(g) + 3H2(g) Ni CH4(g) + H2O (g)

  • 2SO2(g) + O2(g) V2O5 2SO3(g)


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69.

According to the adsorption theory of catalysis the speed of the reaction increase because

  • the concentration of reactant molecules at the active centres of the catalyst becomes high due to adsorption

  • in the process of adsorption, the activation energy of the molecules becomes large

  • absorption produces heat which increases the speed of the reaction

  • adsorption lowers the activation energy of the reaction


70.

Which of the following will have the highest coagulating power for As2S3 colloid?

  • PO43-

  • SO42-

  • Al3+

  • Na+


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