-
Why are substances like platinum and palladium often used for carrying out electrolysis of aqueous solutions?
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Why does physisorption decrease with increase of temperature?
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Why are powdered substances more effective adsorbents as compared to their crystalline forms?
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Why is it necessary to remove CO when ammonia is obtained by Haber's process?
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Why is ester hydrolysis slow in the beginning and becomes fast after some time?
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What is the role of desorption in the process of catalysi?
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What modification can you suggest in the Hardy Schulze law?
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Why is it essential to wash the precipitate with water before estimating it quantitatively?
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Distinguish between the meaning of the terms adsorption and absorption. Give one example of each.
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What is the different between physical adsorption and chemisorption?
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Give reason why a finally divided substance more effective as an adsorbent.
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What are the factors which influence the adsorption of a gas on a solid?
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What is an adsorption isotherm? Describe Freundlich adsorption isotherm.
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What do you understand by activation of adsorbent? How is it achieved?
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What role does adsorption play in heterogeneous catalysis?
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Why is adsorption always exothermic?
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How are the colloidal solutions classified on the basis of physical states of the dispersed phase and dispersion medium?
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Discuss the effect of pressure and temperature on the adsorption of gases on solids.
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What are lyophilic and lyophobic sols? Give an example of each type. Why is hydrophobic sols easily coagulated?
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What is the difference between multimolecular and macromolecular colloids? Give one example of each. How are associated colloids different from these two types of colloids?
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What are enzymes? Write in brief the mechanism of enzyme catalysis.
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How are colloids classified on the basis of (a) physical states of components, (b) nature of dispersion medium and (c) interaction between dispersed phase and dispersion medium.
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Explain what is observed when (i) a beam of light is passed through a colloidal sol; (ii) an electrolyte i.e. NaCI is added to hydrated ferric oxide sol; (iii) electric current is passed through acolloidal sol?
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What are emulsions? What are their different types? Give example of each type.
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What is demulsification? Name two demulsifiers.
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Action of soap is due to emulsification and micelle formation. Comment.
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Give four examples of heterogeneous catalysis.
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What do you mean by activity and selectivity of catalyst?
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Describe some features of catalysis by zeolites.
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What is shape selective catalysis?
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Explain the terms:
(i) Electrophoresis (ii) Coagulation
(iii) Dialysis (iv) Tyndall effect.
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Give four uses of emulsions.
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What are micelles? Give an example of miceller system.
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Explain the terms with suitable examples
(i) Alcosol (ii) Aerosol and (iii) Hydroso
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Comment on the statement that “colloid is nota substance but a state of substance”.
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question_answer36)
Which of the following process does not occur at
the interface of phases?
(a) Crystallisation
(b) Heterogeneous catalysis
(c) Homogeneous
catalysis
(d) Corrosion
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question_answer37)
At the equilibrium position in the process of adsorption..........
(a) 
H > 0 (b)H =
(c) H > (d)H <
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question_answer38)
Which of the following interface cannot be
obtained?
(a) Liquid-liquid
(b) Solid-liquid
(c) Liquid-gas
(d) Gas-gas
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question_answer39)
The term 'sorption' stands for........ .
(a) absorption
(b) adsorption
(c) Both absorption and
adsorption
(d) desorption
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question_answer40)
Extent of physisorption of a gas increases with..........
(a) increase in temperature
(b) decrease in temperature
(c) decrease in surface area of
adsorbent
(d) decrease in strength of van der
Waals' forces
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question_answer41)
Extent of adsorption of adsorbate from solution
phase increases with??..
(a) increase in amount of adsorbate in
solution
(b) decrease in surface area of
adsorbent
(c) increase in temperature of
solution
(d) decrease in amount of adsorbate in
solution
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question_answer42)
Which one of the following is
not applicable to the phenomenon of adsorption?
(a) 
> 0 (b) 
< 0 (c) 
< 0 (d) < 0
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question_answer43)
Which of the following is not a favourable
condition for physical adsorption?
(a) High pressure
(b) Negative AH
(c) Higher critical temperature
of adsorbate
(d) High temperature
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question_answer44)
Physical adsorption of a gaseous species may
change to chemical adsorption with...........
(a) decrease in temperature
(b) increase in temperature
(c) increase in surface area of
adsorbent
(d) decrease in surface area of
adsorbent
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question_answer45)
In physisorption adsorbent does not show
specificity for any particular gas because.........
(a) involved van der Waals' forces are
universal
(b) gases involved behave like
ideal gases
(c) enthalpy of adsorption is
low
(d) it is a reversible process
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question_answer46)
Which of the following is an example of
absorption?
(a) Water on silica gel
(b) Water on calcium chloride
(c) Hydrogen on finely divided
nickel
(d) Oxygen on metal surface
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question_answer47)
On the basis of data given below predict which
of the following gases shows least adsorption on a definite amount of charcoal?
|
Gas
|
Co2
|
SO2
|
CH4
|
H2
|
|
Critical temp./k
|
304
|
630
|
190
|
33
|
(a) CO2 (b) S02
(c) CH4 (d) H2
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question_answer48)
In which of the following reactions
heterogeneous catalysis is involved?
(i) 
(ii) 
(iii) 
(iv) 
(a)'(ii), (iii) (b)
(ii), (iii) and (iv)
(c) (i), (ii) and (iii) (d)
(iv)
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question_answer49)
At high concentration of soap in water, soap
behaves as..........
(a) molecular colloid
(b) associated colloid
(c) macromolecular
colloid
(d) lyophilic colloid
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question_answer50)
Which of the following will show Tyndall effect?
(a) Aqueous solution of soap below
critical micelle concentration
(b) Aqueous solution of soap
above critical micelle concentration
(c) Aqueous solution of sodium
chloride
(d) Aqueous solution of sugar
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question_answer51)
Method by which lyophobic sol can be protected.
(a) By addition of oppositely charged
sol
(b) By addition of an
electrolyte
(c) By addition of lyophilic sol
(d) By boiling
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question_answer52)
Freshly prepared precipitate sometimes gets
converted to colloidal solution by..........
(a) coagulation (b)
electrolysis
(c) diffusion (d)
peptisation
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question_answer53)
Which of the following electrolytes will have
maximum coagulating value for Ag/Ag+ sol?
(a) Na2S (b)
Na3PO4
(c) Na2SO4 (d)
NaCI
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question_answer54)
A colloidal system having a solid substance as a
dispersed phase and a liquid as a dispersion medium is classified as..........
(a) solid sol (b)
gel
(c) emulsion (d)
sol
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question_answer55)
The values of colligative properties of
colloidal solution are of small order in comparison to those shown by true
solutions of same concentration because of colloidal particles..........
(a) exhibit enormous surface area
(b) remain suspended in the
dispersion medium
(c) form lyophilic colloids
(d) are comparatively less in number
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question_answer56)
Arrange the following diagrams in correct
sequence of steps involved in the mechanism of catalysis, in accordance with
modern adsorption theory.
(a) l®ll®lll®IV®V
(b) l®|||®||®|V®V
(c) l®lll®ll®V®IV
(d) |®||®|||®V®IV
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question_answer57)
Which of the following process is responsible
for the formation of delta at a place where rivers meet the sea?
(a) Emulsification (b)
Colloid formation
(c) Coagulation (d)
Peptisation
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question_answer58)
Which of the following curves is in according
with Freundlich adsorption isotherm?
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question_answer59)
Which of the following process is not
responsible for the presence of electric charge on the sol particles?
(a) Electron capture by sol particles
(b) Adsorption of ionic species
from solution
(c) Formation of Helmholtz
electrical double layer
(d) Absorption of ionic species from
solution
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question_answer60)
Which of the following phenomenon is applicable
to the process shown in the figure?
(a) Absorption (b)
Adsorption
(c) Coagulation (d)
Emulsification
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question_answer61)
Which of the following options are correct?
(a) Micelle formation by soap in aqueous
solution is possible at all temperatures
(b) Micelle formation by soap in
aqueous solution occurs above a particular concentration
(c) On dilution of soap solution
micelles may revert to individual ions
(d) Soap solution behaves as a normal
strong electrolyte at all concentrations
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question_answer62)
Which of the following statements are correct
about solid catalyst?
(a) Same reactants may give different
products by using different catalysts
(b) Catalyst does not change of reaction
(c) Catalyst is required in
large quantities to catalyse reactions
(d) Catalytic activity of a solid
catalyst does not depend upon the strength of chemisorption
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question_answer63)
Freundlich adsorption isotherm is given by the
expression 
Which of
the following conclusions can be drawn from this expression?
(a) When 
= 0, the adsorption is
independent of pressure
(b) When = 0, the adsorption is
directly proportional to pressure
(c) When 
vs p graph is a line
parallel to x - axis
(d) When n = 0, plot of
vs p is a curve
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question_answer64)
H2 gas is adsorbed on activated
charcoal to a very little extent in comparison to easily liquefiable gases due to..........
(a) very strong van der Waals'
interaction
(b) very weak van der Waals'
forces
(c) very low critical
temperature
(d) very high critical temperature
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question_answer65)
Which of the following statements are correct?
(a) Mixing two oppositely charged sols
neutralises their charges and stabilises the colloid
(b) Presence of equal and
similar charges on colloidal particles provides stability to the colloids
(c) Any amount of dispersed
liquid can be added to emulsion without destabilising it
(d) Brownian movement stabilises sols
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question_answer66)
An emulsion cannot be broken by ......... and.........
.
(a) heating
(b) adding more amount of
dispersion medium
(c) freezing
(d) adding emulsifying agent
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question_answer67)
Which of the following substances will
precipitate the negatively charged emulsions?
(a) KCI (b)
Glucose
(c) Urea (d)
NaCI
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question_answer68)
Which of the following colloids cannot be
coagulated easily?
(a) Lyophobic colloids
(b) Irreversible colloids
(c) Reversible
colloids
(d) Lyophilic colloids
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question_answer69)
What happens when a Lyophilic sol is added to a
Lyophobic sol?
(a) Lyophobic sol is protected
(b) Lyophilic sol is protected
(c) Film of lyophilic sol is
formed over lyophobic sol
(d) Film of lyophobic sol is formed over
lyophilic sol
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question_answer70)
Which phenomenon occurs when an electric field
is applied to a colloidal solution and electrophoresis is prevented?
(a) Reverse osmosis takes place
(b) Electroosmosis takes place
(c) Dispersion medium begins to
move
(d) Dispersion medium becomes stationary
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question_answer71)
In a reaction, catalyst changes..........
(a) physically (b)
qualitatively
(c) chemically (d)
quantitatively
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question_answer72)
Which of the following phenomenon occurs when a
chalk stick is dipped in ink?
(a) Adsorption of coloured substance
(b) Adsorption of solvent
(c) Absorption and adsorption
both of solvent
(d) Absorption of solvent
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question_answer73)
Why is it important to have clean surface in
surface studies?
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question_answer74)
Why is chemisorption referred to as activated
adsorption?
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question_answer75)
What type of solutions are formed on dissolving
different concentrations of soap in water?
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question_answer76)
What happens when gelatin is mixed with gold
sol?
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question_answer77)
How does it become possible to cause artificial
rain by spraying silver iodide on the clouds?
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question_answer78)
Gelatin which is a peptide is added in
ice-creams. What can be its role?
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question_answer79)
What is collodion?
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question_answer80)
Why do we add alum to purify water?
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question_answer81)
What happens when electric field is applied to
colloidal solution?
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question_answer82)
What causes Brownian motion in colloidal
dispersion?
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question_answer83)
A colloid .is formed by adding 
in excess of hot
water. What will happen if excess sodium chloride is added to this colloid?
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question_answer84)
How do emulsifying agents stabilise the
emulsion?
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question_answer85)
Why are some medicines more effective in the
colloidal form?
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question_answer86)
Why does leather get hardened after tanning?
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question_answer87)
How does the precipitation of colloidal smoke
take place in Cottrell precipitator?
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question_answer88)
How will you distinguish between dispersed phase
and dispersion medium in an emulsion?
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question_answer89)
On the basis of Hardy-schuize rule explain why
the coagulating power of phosphate is higher than chloride?
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question_answer90)
Why does bleeding stop by rubbing moist alum?
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question_answer91)
Why is 
colloid positively
charged, when prepared by adding to
hot water?
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question_answer92)
Why do physisorption and chemisorption behave
differently with rise in temperature?
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question_answer93)
What happens when dialysis is prolonged?
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question_answer94)
Why does the white precipitate of silver halide
become coloured in the presence of dye eosin?
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question_answer95)
What is the role of activated charcoal in gas
mask used in coal mines?
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question_answer96)
How does a delta form at the meeting place of
sea and river water?
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question_answer97)
Give an example where physisorption changes to
chemisorption with rise in temperature. Explain the reason for change.
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question_answer98)
Why is desorption important for a substance to
act as good catalyst?
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question_answer99)
What is the role of diffusion in heterogeneous
catalyst?
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question_answer100)
How does a solid catalyst enhance the rate of
combination of gaseous molecules?
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question_answer101)
Do the vital functions of the body such as
digestion get affected during fever? Explain your answer.
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question_answer102)
Method of formation of solution is given in Column
I. Match it with the type of solution given in Column II.
|
|
Column 1
|
Column 11
|
|
A.
|
Sulphur vapours passed through cold water.
|
1. Normal electrolyte solution
|
|
B.
|
Soap mixed with water above critical micelle
concentration.
|
2. Molecular colloids
|
|
C.
|
White of egg whipped with water.
|
3. Associated colloid
|
|
P
|
With water below critical
|
4. Macromolecular colloids
|
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question_answer103)
Match the statement given in Column I with the
phenomenon given in Column II.
|
|
Column 1
|
Column 11
|
|
A.
B.
C.
D.
|
Dispersion medium moves in an electric field.
Solvent molecules pass through semipermeable membrane
towards solvent side.
Movement of charged colloidal particles under the
influence of applied electric potential towards oppositely charged
electrodes.
Solvent molecules pass through semipermeable
membranes towards solution side.
|
1. Osmosis
2. Electrophoresis
3. Electroosmosis
4. Reverse-osmosis
|
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question_answer104)
Match the items given in Column I and
Column II.
|
|
Column 1
|
Column 11
|
|
A.
B.
C.
D.
|
Protective colloid Liquid-liquid colloid
Positively charged colloid Negatively charged colloid
|
Lyophilic colloids Emulsion
 +
hot water
|
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question_answer105)
Match
the types of colloidal systems given in Column I with the name given in Column
II.
|
|
Column
1
|
Column
11
|
|
A.
B.
C.
D.
|
Solid
in liquid
Liquid
in solid
Liquid
in liquid
Gas
in liquid
|
1. Foam
2.
Sol
3.
Gel
4.
Emulsion
|
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question_answer106)
Match the items of Column I and Column II.
|
|
Column 1
|
Column 11
|
|
A.
B.
C.
D.
|
Dialysis Peptisation Emulsification
Electrophoresis
|
Cleansing action of soap Coagulation Colloidal
sol formation Purification
|
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question_answer107)
Match the items of Column I and Column Il
|
|
Column 1
|
Column 11
|
|
A.
B.
C.
D.
|
Butter
Pumice stone
Milk
Paints
|
1. Dispersion of liquid in liquid
2.Dispersion of solid in liquid
3.Dispersion of gas in solid
4.Dispersion of liquid in solid
|
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question_answer108)
Assertion (A) An ordinary filter paper
impregnated with collodion solution stops the flow of colloidal particles.
Reason (R) Pore size of the
filter paper becomes more than the size of colloidal particle.
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question_answer109)
Assertion. (A) Colloidal solution show
colligative properties.
Reason (R) Colloidal particles are
large in size.
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question_answer110)
Assertion (A) Colloidal solutions do not
show Brownian motion.
Reason (R) Brownian motion is
responsible for stability of sols.
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question_answer111)
Assertion (A) Coagulation power of 
is more than
.
Reason (R) Greater the valency of
the flocculating ion added, greater is its power to cause precipitation
(Hardy-SchuIze rule) .
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question_answer112)
Assertion (A) Detergents with low CMC are
more economical to use.
Reason (R) Cleansing action of
detergents involves the formation of micelles. These are formed when the
concentration of detergents
becomes equal to CMC.
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question_answer113)
What is the role of adsorption in heterogeneous
catalysis?
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question_answer114)
What are the applications of adsorption in
chemical analysis?
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question_answer115)
What is the role of adsorption in froth
floatation process used especially for concentration of sulphide ores?
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question_answer116)
What do you understand by shape selective
catalysis? Why are zeolites good shape selective catalysts?
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