NCERT Class 12 Chemistry Short Questions & Answers 2021 NCERT Class 12 Chemistry Questions & Answers NCERT Solutions For Class 12 Chemistry Chapter 5 Surface Chemistry Important Questions for Class 12 Chemistry Surface Chemistry Class 12 Important Questions 2021
51. Which of the following is an emulsifier?
(a)Soap
(b) Water
(c) Oil
(d) NaCl
52. Haemoglobin is an example of
(a) Lyophilic Sol
(b) Lyophoblic Sol
(c) Protective Sol
(d) Coagulation of blood
53. Which of the following is not a method for coagulation?
(a) By heating or cooling
(b) By electrophoresis
(c) By exposure to light
(d) By ultrafiltration
54. Protective action of a colloid can be measured in terms of
(b) Congo robin number
(a) Gold Number
(c) Both (a) & (b) (c) Micelle number
55. Emulsifier is used to
(a) Stabilise emulsion
(b) Stabilise gel
(c) Both (a) & (b)
(d) Stabilise sol
56. Which of the following is not an oil in water emulsion?
(b) Milk
(a) Butter
(c) Cod liver oil
(d) Cold Cream
57. The ion in potash alum acting as coagulant used for purification of drinking water is
(a) K
(b) AP
(c) SO,2
(d) All of these
58. Aluminium hydroxide is used as a
in dyeing.
(a) Mordant
(b) Chromophore
(c) Auxochrome
(d) Can’t be said
59. is a surface phenomena.
(a) Absorption
(b) Adsorption
(c) Both (a) & (b)
(d) none of these
60. Ink is soaked by a chalk due to
(a) Absorption
(b) Adsorption
(C) Sorption
(d) both (a) and (b)
61. Which of the following is not applicable for physisorption?
(a) It involves Vander Waal’s force
b) It is reversible in nature
(c) It forms mono-molecular layer
(d) State of adsorbate is same as in bulk
62. Which of the following is not applicable for chemisorption
(a) Heat of adsorption is in the order 200-400 KJ/mol
(b) It is not specific in nature
(c) It occurs at high Temperature
(d) Rate of adsorption a Pressure
63. Which of the following statements is correct?
(a) Higher the critical temperature, more easier is the liquification & more readily is the adsorption of gas
(b) adsorption of gas is independent of critical temperature
(c) Adsorption of gas is independent of pressure
(d) The adsorption may be endothermic
64. Milk is an example of
(a) Oil in water emulsion
(b) Oil in oil emulsion
(c) Water in oil emulsion
(d) Water in water emulsion
65 When alum is added to clay water, coagulation takes place because
(a) The clay particles are further subdivided
(b) The charge carried by clay particles is neutralised
(c)The density of water decreases
(d) none of these
66. Freshly prepared precipitates can be easily dispersed by shaking it with dispersion medium. The process is called
(a) Peptisation
(b) Electrophoresis
(c) Dispersion
(d) Dialysis
67. Example of a liquid as dispersion medium in colloidal system is
(a) Smoke
(b) Milk
(d) Cheese
(c) Fog
68. The presence of electric charge on the colloidal particle is indicated by the experiment
(b) Electrolysis
(a) Osmosis
(d) Electrophoresis
(c) Dialysis
69. Number of phases in a colloidal system is
(b) 2
(a) 1
(d) 4
(c) 3
70. Fog is a colloidal solution of.
(a)Gas in Liquid (b) Liquid in Gas
(d) Solid in Gas
(c) Gas in solid
71. The process of separation of colloids by passing through a semi-permeable membrane is called
(b) Electrophoresis
(a) Filtration
(d) Ultrafiltration
(c) Dialysis
72. The movement of colloidal particles under the influence of applied electric field is called
(b) Tyndall effect
(a) Dialysis
(c) Electrophoresis (d) Emulsion
73. An example of micelle 1s
(a) Sodium sterate
(b) Gold sol
(c) Solution of NaCI
(d) Ruby glass
74. The average molecular mass of colloidal particles can be accurately measured by
(b) Tyndal effect
(a) Osmotic pressure
(C)Brownian movement (d) Floculation value
75. Which of the following electrolytes will be most effective in causing coagulation of a positively
charged Fe(OH), Sol ?
(a) K,SO,
(b) K,[Fe(CN),]
(c) KCI
(d) K,C0,
76. On addition of 1ml solution of 10% NaCl to 10 ml Gold Sol in presence of 0.0250g of starch, the
coagulation is just prevented. Starch has Gold number
(a) 0.025
(b) 0.25
(c) 2.5
(d) 25
77. Which of the following is an example of associated colloid ?
(a) Protein + water
(b) Soap +water
(c)Rubber+ Benzene (d) As,O, + Fe(OH),
78. Which of the following will be most effective in coagulation of Gold Sol ?
(a) NaNO,
(b) K[Fe(CN)²]
(c) Na PO
(d) MgCl,
79. Alums purify muddy water by
(a) Dialysis
(b) Adsorption
(c) Coagulation (d) Forminga true solution
80.Which of the following is an example of associated colloid?
(a) Starch
(b) Sodium lauryl sulphate
(c) Sulphur
(d) Polythene
81. When Kl is added to AgNO, solution, the Sol formed may be written as
(a) Agl/
(b) Agl /Ag’
(d) Agl.KNO,
(c) Agl NO
82. Soap removes grease by
(a) Adsorption
(b) Emulsification
(c) Coagulation
(d) None of these
83. Which of the following reaction gives a colloidal solution?
(a) MgCO, > MgO+CO,
(b) 2Na +2H,02NaOH + H,
(C) 2HNO, +3H,S3S + 4H,0+ 2NO
(d) Cu+ CuCl, Cu,C1,
84 The As²S³, solution is charged due to the adsorption of_________________ion.
(a) S²-
(b) OH-
(d) As3+
(c) H+
85. The method commonly employed for the destruction of a colloidal solution is
(a) Addition of an electrolyte
(b) Diffusion through animal membrane
(c) Condensation (d) Dialysis
86. Which of the following is not correct regarding the adsorption of a gas on the surface of a solid?
(a) On increasing temperature adsorption increases continuously
(b) Enthalpy & entropy changes are negative
(c) Adsorption is more for specific substance
(d) It is a reversible reaction.
of charged particles on
87. Peptisation is due to a surface.
(a) absorption
(b) adsorption
(c) coagulation
(d) condensation
88. Which is an emulsion?
(a) Boot polish
(b) Lipstick
(c) Shampoo
(d) all of these
89. The size of colloidal particles is
(a) less than true solution particles
(b) less than suspension particles
(c) greater than suspension particles
(d) none of these
90. Which is not a colloid?
(a) Egg white
(b) milk
(c) Ruby glass
(d) FeCl
91. Solvent hating colloids are
(a) lyophobic
(b) lyophilic
(c) hydrophilic
(d) none of these
92. Tails of comets are visible due to
(a) Tyndal effect
(b) Brownian movement
(c) reflection
(d) all of these
93. Foam is a colloidal solution of
(a) gaseous particles dispersed in gas
(6) gaseous particles dispersed in a liquid
(c) solid particles dispersed in a liquid
(d) solid particles dispersed in a gas
94. Medicines are more effective if they are used in
(a) colloidal state
(b) solid state
(c) solution state
(d) cannot be predicted
95. Brownian movement of particles is the property of colloidal solutions.
(a) optical
(b) electrical
(c) mechanical
(d) none of these
ANSWER:-
51. (d) 52. (c) 53. (b) 54. (a) 55. (c) 56. (a) 57. (c) 58. (c) 59.(b) 60. (c) 61. (a) 62. (a) 63. (a) 64. (a) 65. (b) 66. (a) 67. (b) 68. (d) 69. (b) 70. (b) 71. (c) 72. (c) 73. (a) 74. (a) 75. (b) 76. (d) 77. (b) 78. (d) 79. (c)80. (b)81. (b) 82. (b) 83. (c) 84. (a) 85. (a) 86. (a) 87. (b) 88. (d) 89. (b) 90. (d) 91. (a) 92. (a) 93. (b) 94. (a) 95. (c)