Surface Chemistry – 1

1) Zeolites have high porosity due to their
a) one dimensional network
b) two dimensional network
c) three dimensional network
d) all the above

2) Digestion of fats in the intestine is facilitated by
a) coagulation
b) peptisation
c) precipitation
d) emulsification

3) Collodion is obtained by
a) electro dialysis of cellulose nitrate
b) peptisation of cellulose nitrate with ethyl alcohol
c) dispersion of cellulose acetate
d) passing a beam of light into cellulose nitrate

4) The cleaning action of soap is by
a) emulsification
b) peptisation
c) coagulation
d) Cotrell precipitation

5) Which is not a colloidal system?
a) liquid-liquid
b) solid-solid
c) gas-gas
d) solid-liquid

6) Fog is a colloidal system in which the dispersed phase and dispersion medium respectively are
a) gas-liquid
b) liquid-gas
c) solid-gas
d) gas-solid

7) The diameter of colloidal particles is in the range of
a) 1 to 100 nm
b) 500-1000 nm
c) 1 to 100 cm
d) 500-1000 cm

8) The adsorption isotherm is a curve obtained by plotting
a) x/m , n
b) x/m, t
c) x/m.p
d) x/m,k

9) Which is not true of physical adsorption?
a) low heat of adsorption
b) reversible equilibrium is attained
c) forms monomolecular layers
d) no specific features

10) Ferric chloride is applied to stop bleeding because
a)
b)
c)
d)

11) The zig-zag movement of the colloidal particles in a colloidal sol was observed by
a) Zsigmondy
b) Ostwald
c) Robert Brown
d) Tyndall

12) The zig-zag movement of the colloidal particles in a colloidal sol is due to the
a) Air currents striking the sol
b) Lightness of their mass
c) Net force of surface tension acting downwards
d) Hitting of the colloidal particles by the molecules of the dispersion medium

13) Arsenic sulphide sol is prepared by passing H2S through arsenic oxide solution. The charge developed on the particles is due to the adsorption of
a)
b)
c)
d)

14) The charge on the colloidal particles can be determined by
a) Electrophoresis
b) Electro-dialysis
c) Geiger – Muller Counter
d) Mulliken oil drop experiment

15) Which of the following sols is positively charged in terms of its colloidal particles?
a) Gold sol
b) Silicic acid
c) Starch sol
d) Prussian blue

16) Zeta potential (or electrokinetic potential) is the
a) Potential required to bring about coagulation of a colloidal sol
b) Potential required to give the particles a speed of 1 cm/sec in the sol
c) Potential difference between the fixed charged layer and the diffused layer having opposite charge
d) Potential energy of the colloidal particles

17) The movement of colloidal particles under the influence of an electric field is called
a) Electrophoresis
b) Electrolysis
c) Electro-dialysis
d) Electro-osmosis

18) Which of the following does not have a hydrophobic structure?
a) Linseed oil
b) Lanolin
c) Glycogen
d) Rubber

19) The arsenious sulphide sol has -ve charge. The maximum power to precipitate it is possessed by
a)
b)
c)
d)

20) The capacity of an ion to coagulate a colloidal solution depends on
a) Its size only
b) The magnitude of charge on it
c) Both the size of the ion and the magnitude of charge on it
d) Both its magnitude and the sign of charge

21) The method which does not result in sol destruction is
a) Electrophoresis
b) Addition of electrolyte
c) Diffusion through an animal membrane
d) Mixing two oppositely charged sols

22) Which of the following has maximum flocculation value for a negatively charged sol?
a) NaCl
b)
c)
d) Kcl

23) Which of the following ions has the minimum flocculation value?
a)
b)
c)
d)

24) The minimum flocculation power of KCl, MgCl2, CrCl3 and SnCl4 for a positively charged sol are in the order
a)
b)
c)
d)

25) The flocculation value of an electrolyte is
a) The amount of electrolyte in grams required to bring about coagulation of 1 litre of colloidal sol
b) The amount of electrolyte in milligrams to bring about coagulation of 10 ml of the colloidal sol
c) The amount of electrolyte in millimoles required to bring about coagulation of one litre of the colloidal sol
d) The reciprocal of coagulating power

26) The gold number is the index for
a) A protective colloid
b) the gold present in ornaments
c) the extent of gold plating done
d) the weight of gold in milligrams present per litre of a gold sol

27) A gold number is assigned to
a) Lyophobic colloids only
b) Lyophilic colloids only
c) Both Lyophilic and Lyophobic colloids
d) None of the above

28) Which one of the following statements is wrong?
a) The greater the gold number of a protective colloid, the less is its protective power
b) The Hardy- Schulze rule is applicable only to the coagulation of a lyophilic sol
c) The greater flocculation value of an electrolyte means its poor coagulating power
d) For coagulating a positive sol, the positive ions of the electrolyte have no significance

29) The Cottrell precipitator is a device to
a) Coagulate the particles of any sol
b) Coagulate the particles of carbon from smoke
c) Coagulate the mud particles from water
d) Coagulate the dirt particles of sewage water

30) The blue colour of the sky is due to
a) Absorption of light by dust particles
b) Reflection of light by dust particles
c) Scattering of light by dust particles
d) Presence of clouds which are a colloidal dispersion of water particles in air

31) Applying ferric chloride solution in the laboratory can stop bleeding due to a cut. This is due to
a)
b)
c) Reaction taking place between ferric ions and the haemoglobin forming a complex
d)

32) Which of the following is a homogeneous system?
a) Muddy water
b) Bread
c) Concrete
d) A solution of sugar in water

33) In the Faraday-Tyndall Effect the colloidally suspended particles
a) Trace the path of a strong beam of light
b) Coagulate
c) Show electrophoresis
d) Show Brownian movement

34) The separation of colloidal particles from those of molecular dimensions using electricity is known as
a) Electrolysis
b) Electrophoresis
c) Electro-dialysis
d) None of the above

35) The isoelectric point is the pH at which colloidal particles
a) Coagulate
b) Become electrically neutral
c) Can move towards either electrode
d) All of these

36) The Tyndall effect in a colloidal solution is due to the
a) Scattering of light
b) Reflection of light
c) Absorption of light
d) Presence of electrically charged particles

37) The difference between colloids and crystalloids is of
a) Diameter
b) Particle size
c) Radius
d) Solubility

38) Which reaction requires a catalyst?
a)
b)
c)
d) All

39) A catalyst in a reaction
a) Increases the activation energy of the forward reaction
b) Increases the activation energy of the backward reaction
c) Increases the activation energy of both the reactions
d) Decreases the activation energy of both the reactions

40) A catalyst in a reaction changes which of the following?
a) Equilibrium constant
b) Entropy
c) Rate constant
d) Nature of products

41) Consider the following reactions

  1. The reactions, which require a catalyst, are

a) (A) and (C)
b) (B) and (D)
c) (A) and (B)
d) All of these

42) During hydrogenation of oils, which one of the following catalysts is used?
a) Palladium
b) Nickel
c) Iron
d)

43) Pick out the correct statement.
a) A catalyst speeds up the reaction by increasing the activation energy
b) A catalyst speeds up the reaction by decreasing the activation energy
c) A catalyst speeds up the reaction by providing an alternate path of lower activation energy
d) A catalyst alters the positions of equilibrium

44) Which is the characteristic of a catalyst?
a) It changes the equilibrium point
b) It initiates the reaction
c) It alters the rate of reaction
d) It increases the average K.E of molecules

45) Which one of the following statements regarding catalysis is not true?
a) A catalyst remains unchanged at the end of the reaction
b) A catalyst can initiate a reaction
c) A catalyst does not alter the equilibrium in a reversible reaction
d) Catalysts are sometimes very specific in terms of reactions

46) In chemical reaction, a catalyst
a) Alters the amount of the products
b) Lowers the activation energy
c)
d)

47) ZSM-5 converts
a) Alcohol to petrol
b) Benzene to toluene
c) Toluene to benzene
d) Heptane to toluene

48) A catalyst only
a) Decreases activation energy
b) Increases activation energy
c) Brings about equilibrium
d) None of these

49) The term catalyst was given by
a) Rutherford
b) Berzelius
c) Wohler
d) Kolbe

50) Which of the following kinds of catalysis can be explained by the adsorption theory ?
a) Homogeneous catalysis
b) Acid-Base catalysis
c) Heterogeneous catalysis
d) Enzyme catalysis

51) A catalyst increases the rate of reaction by
a) Decreasing the enthalpy
b) Decreasing the internal energy
c) Decreasing the activation energy
d) Increasing the activation energy

52) The role of a catalyst in a reversible reaction is to
a) Increase the rate of the forward reaction
b) Decrease the rate of the backward reaction
c) Alter the equilibrium constant of the reaction
d) Allow the equilibrium to be achieved quickly

53) A biological catalyst is essentially
a) An enzyme
b) A carbohydrate
c) An amino acid
d) A nitrogenous base

54) In the adsorption of acetic acid by charcoal, which one of the following statements is wrong?
a) Charcoal is called an adsorbent
b) Acetic acid is called the adsorbate
c) The concentration of acetic acid solution decreases
d) The concentration of acetic acid solution increases

55) Which one of the following is a case of absorption?
a)
b) Silica gel in contact with water vapour
c) Ammonia gas in contact with water
d) Cotton clothes dipped in a dye solution

56) Negative adsorption implies that
a) Solvent from the solution is adsorbed on the solid absorbent
b) A part of the solid adsorbent passes into the solution
c) Adsorption is less than the expected value
d) The concentration of the solute in the solution has become less after adsorption

57) Which one of the following is a case of negative adsorption?
a) Acetic acid solution in contact with animal charcoal
b) Dilute KCl solution in contact with blood charcoal
c) Concentration KCl solution in contact with blood charcoal
d)

58) The volumes of gases H2, CH4, CO2 and NH3 adsorbed by 1g of charcoal at 288K are in the order:
a)
b)
c)
d)

59) Which one of the following statements is wrong?
a) Physical adsorption of a gas is directly related to its critical temperature
b) Chemical adsorption decreases regularly as the temperature is increased
c) Adsorption is an exothermic process
d) A solid with a rough surface is a better adsorbent than the same solid with a smooth surface

60) Which one of the following is wrong about physical adsorption?
a)
b) It has a low heat of adsorption
c) It is reversible in nature
d) It forms a unimolecular layer on the surface of the adsorbent

61) Which one of the following is wrong about chemisorption?
a) It involves the formation of a compound on the surface of the solid adsorbent
b) It is specific in nature
c) It first increases with increase of temperature and then decreases
d) It is reversible in nature

62) The Freundlich adsorption isotherm gives a straight line on plotting
a)
b)
c)
d)

63) The plot of vs temperature at constant pressure is called the
a) Adsorption isotherm
b) Adsorption isobar
c) Adsorption isochore
d) Freundlich isotherm

64) Chemical adsorption
a) Decreases with increase of temperature
b) Increase with increases of temperature
c) First increases and then decreases with increase of temperature
d) First decreases and then increases with increase of temperature

65) The colouring matter removed by animal charcoal during clarification of sugar
acts as the

a) Adsorbate
b) Adsorbent
c) Adsorber
d) Catalyst

66) Which of the following can adsorb a large volume of hydrogen gas?
a) Colloidal solution of palladium
b) Finely divided nickel
c) Colloidal ferric hydroxide
d) Finely divided platinum

67) Which one of the following substances adsorbs hydrogen gas most strongly?
a) Activated carbon
b) Silica gel
c) Platinum black
d) Iron powder

68) Which of the following is less than zero during adsorption?
a)
b)
c)
d) All the above

69) For the adsorption of a gas on a solid, the plot of log x/m vs log P is linear with slope equal to (n being whole number)
a) k
b) log k
c) n
d) 1/n

70) Which is adsorbed in the maximum amount by activated charcoal?
a)
b)
c)
d)

71) In physical adsorption, gas molecules are bound on the solid surface by
a) Chemical forces
b) Electrostatic forces
c) Gravitational forces
d)

72) How many layers are adsorbed in chemical adsorption ?
a) One
b) Two
c) Many
d) Zero

73) The heats of adsorption in physisorption lie in the range (in kJ/mol)
a) 40-400
b) 40-100
c) 10-40
d) 1-10

74) In physical adsorption the forces associated are
a) Ionic
b) Covalent
c) Van der Waal
d) Hydrogen bonding

75) @ 50 ml of 1 M oxalic acid is shaken with 0.5 g wood charcoal. The final concentration of the solution after adsorption is 0.5 M. What is the amount of oxalic acid absorbed per gm of carbon?
a) 3.15 g
b) 3.45 g
c) 6.30 g
d) None

76) The effect of pressure on adsorption is high if the
a) Temperature is low
b) Temperature is high
c) Temperature is neither very low nor very high
d) Charcoal piece is used instead of charcoal powder

77) Colloidal particles have their size in the range
a) 1 nm – 10 nm
b) 10 nm – 100 nm
c) 1 nm – 100 nm
d) 10 nm – 1000 nm

78) Which one of the following is not a property of hydrophilic sols?
a) A high concentration of the dispersed phase can be easily attained
b) Coagulation is reversible
c) The viscosity and surface tension are about the same as for water
d) The charge of the particle depends upon the pH value of the medium:; it may be positive, negative or even zero

79) Smoke is a colloidal dispersion of
a) A gas in a solid
b) A solid in a gas
c) A gas in a gas
d) A liquid in a gas

80) The colloidal dispersion of solid in a gas is called a/an
a) Foam
b) Aerosol
c) Gel
d) Sol

81) Milk is an example of a/an
a) Gel
b) Sol
c) Foam
d) Emulsion

82) Multimolecular colloids are present in a
a) Sol of sulphur
b) Sol of proteins
c) Sol of gold
d) Both (a) and (c)

83) Butter is an example of a/an
a) Gel
b) Emulsion
c) Sol
d) Foam

84) An emulsion is a colloidal dispersion of
a) A liquid in a gas
b) A liquid in a liquid
c) A solid in a liquid
d) A gas in a solid

85) The solution of rubber in benzene is an example of
a) a multimolecular colloid
b) a macromolecular colloid
c) An associated colloid
d) a lyophobic colloid

86) Micelles constitute an example of
a) Multimolecular colloids
b) Macromolecular colloids
c) Associated colloids
d) None of these

87) Lyophilic sols are more stable than lyophobic sols because
a) The colloidal particles have positive charge
b) The colloidal particles have no charge
c) The colloidal particles are solvated
d) There are strong electrostatic repulsions between the negatively charged colloidal particles

88) Which one of the following is not a colloid?
a) Ruby glass
b) Smoke
c) Haemoglobin
d) Chlorophyll

89) Collodion is a colloidal solution of
a) Starch in water
b) Cellulose in water
c) Cellulose nitrate in water
d) Cellulose nitrate in ethyl alcohol

90) A colloidal sol found effective in treating eye disease is
a) Colloidal sulphur
b) Colloidal antimony
c) Colloidal gold
d) Colloidal silver

91) Lyophobic colloids show
a) No interaction with the dispersion medium
b) Medium-range interaction with the dispersion medium
c) Strong interactions with the dispersion medium
d) Strong electrostatic repulsions between the negatively charged colloidal particles

92) Which of the following is not a colloid?
a) Latex
b) Blood
c) Butter
d) Ghee

93) The process of preparation of a colloidal sol from a precipitate is called
a) Coagulation
b) Dissolution
c) Dispersion
d) Peptisation

94) Bredigs arc method cannot be used for the preparation of a colloidal sol of
a) Copper
b) Iron
c) Silver
d) Sodium

95) To the solution of sulphur in alcohol, a small amount of water is added. Which of the following will happen?
a) It will become a suspension
b) It will become a colloidal sol
c) It will remain a true solution
d) It will be something between a true solution and a colloidal sol

96) The separation of colloidal particles from those of molecular dimensions is known as
a) Photolysis
b) Dialysis
c) Pyrolysis
d) Peptisation

97) A negatively charged suspension of clay in water will need the minimum amount of … for precipitation
a) Aluminium chloride
b) Potassium sulphate
c) Sodium hydroxide
d) Hydrochloric acid

98) Which one of the following substances gives a positively charged sol?
a) Gold
b) A metal sulphide
c) Ferric hydroxide
d) An acidic dye

99) On adding a few drops of dil. HCl to freshly precipitated ferric hydroxide, a red coloured colloidal solution is obtained. This phenomenon is known as
a) Peptisation
b) Dialysis
c) Protective action
d) Dissolution

100) An emulsifier is a substance
a) Which can convert every liquid into an emulsion
b) Which breaks the emulsion into its constituent liquids
c) Which stabilizes an emulsion
d) Which brings about coagulation of an emulsion


Answer

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