The separation of colloidal particles (or purification of sol) from particles of molecular dimensions is known as:
Photolysis
Dialysis
Pyrolysis
Peptization
Lyophilic sols are:
Irreversible sols
They are prepared from inorganic compounds
Not coagulated by adding electrolytes
Self-stabilizing
The volume of colloidal particles Vc as compared to the volume of solute particles in true solution Vs could be:
~1
~103
~102
~10-3
The dispersed phase in colloidal iron (III) hydroxide and colloidal gold is positively and negatively charged respectively, which of the following statement is not correct?
MgCl2 solution coagulates gold sol readily than iron (III) hydroxide sol at pH = 7
Na2SO4 solution causes coagulation in both sol
Mixing of two sols have no effect
Coagulation in both sol can be brought about by electrophoresis
Pick out the wrong statement.
Micelles are formed by surfactant molecules above the Critical Micelle Concentration (CMC)
The conductivity of a solution having surfactant molecules decreases sharply at the CMC
Lower is the CMC of detergent, more is its detergency
Cleansing action is not related to micelles
The correct match among the following options is:
1.
Solid sol
-
Smoke
2.
butter
3.
Foam
Mist
4.
Whipped cream
sol
The coagulation values in millimoles per liter of the electrolytes used for the coagulation of As2S3 are given below
(I) (NaCl)=52 , (II) (BaCl2)=0.69 , (III) (MgSO4)=0.22
The correct order of their coagulating power is -
III > II > I
I > II > III
I > III > II
II > III>I
Process in which catalyst has a different phase to a reaction mixture this process is known as
Homogenous catalysis
Heterogenous catalysis
Hypergenous catalysis
Hypogenous catalysis
Why is chemisorption referred to as activated adsorption?
Chemical bond formation between reactant and adsorbent molecules.
Chemical bond formation between product and adsorbent molecules.
Chemical bond formation between reactant and product molecules.
None of the above
The correct statement among the following about Collodion is -
4% solution nitro-cellulose in a mixture of ethyl alcohol and ether.
14% solution nitrate in a mixture of ether and ethanol.
20 % solution nitrate in a mixture of propanol and diethyl ether.
None of the above.
A colloidal system having a solid substance as a dispersed phase and a liquid as a dispersion medium is classified as .........
Gel
Emulsion
Sol
The process responsible for the formation of delta at a place where rivers meet the sea is
Emulsification
Colloid formation
Coagulation
Peptisation
The curve that represents Freundlich's adsorption isotherm is -
The phenomenon that is applicable to the process shown in the figure is :
Absorption
Adsorption
At the equilibrium position in the process of adsorption ..........
ΔH > 0
ΔH = TΔS
ΔH > TΔS
ΔH < TΔS
The process that does not occur at the interface of phases is :
Crystallisation
Heterogeneous catalysis
Homogeneous catalysis
Corrosion
The interface that cannot be obtained is
Liquid-liquid
Solid-liquid
Liquid-gas
Gas-gas
The term ‘sorption’ stands for.........
Both absorption and adsorption
Desorption
Extent of adsorption of adsorbate from solution phase increases with...
Physical adsorption is not favoured by :
High pressure.
Negative ∆H
Higher critical temperature of adsorbate.
High temperature.
Extent of physisorption of a gas increases with ......
Increase in temperature.
Decrease in temperature.
Decrease in surface area of adsorbent.
Decrease in strength of van der Waals’ force.
An emulsion cannot be broken by ............. and ................
Heating.
Adding more amount of dispersion medium.
Freezing.
Centrifugation
Physical adsorption of a gaseous species may change to chemical adsorption with ..........
Increase in surface area of adsorbent.
In physisorption adsorbent does not show specificity for any particular gas because..........
Involved van der Waals’ forces are universal.
Gases involved behave like ideal gases.
Enthalpy of adsorption is low.
It is a reversible process.
Among the following options the example of absorption is :
Water on silica gel.
Water on calcium chloride.
Hydrogen on finely divided nickel.
Oxygen on metal surface.
On the basis of data given below, the gas which shows the least adsorption on a definite amount of charcoal is-
Gas
CO2
SO2
CH4
H2
Critical temp./K
304
630
190
33
At high concentration of soap in water, soap behaves as .......
Molecular colloid.
Associated colloid.
Macromolecular colloid.
Lyophilic colloid.
Tyndall effect is shown by
Aqueous solution of soap below critical micelle concentration.
Aqueous solution of soap above critical micelle concentration.
Aqueous solution of sodium chloride.
Aqueous solution of sugar.
Method by which lyophobic sol can be protected.
By addition of oppositely charged sol.
By addition of an electrolyte.
By addition of lyophilic sol.
By boiling.
Freshly prepared precipitate sometimes gets converted to colloidal solution by ......
Electrolysis
Diffusion
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