Surface Chemistry PYQs Set 3 (PDF)

Set 3 of 9 · Questions 61-90 of 248

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Surface Chemistry · Set 3 (Q61-90)
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61. $Among the electrolytes N a_{2} S O_{4}, C a C l_{2}, A l_{2} (S O_{4})_{3} and N H_{4} Cl, the most effective coagulating agent for S b_{2} S_{3} sol is:$ (1) $N a_{2} S O_{4}$ (2) $C a C l_{2}$ (3) $A l_{2} (S O_{4})_{3}$ (4) $N H_{4} Cl$ 62. $Match the catalysts (Column I) with products (Column II). Column I (1) V_{2} O_{5} (2) TiC l_{4} / Al (Me)_{3} (3) PdC l_{2} (4) Iron Oxide ColumnII (i) Polyethylene (ii) ethanol (iii) H_{2} S O_{4} (iv) N H_{3}$ (1) $(1) - (iii), (2) - (iv), (3) - (i), (4) - (ii)$ (2) $(1) - (ii), (2) - (iii), (3) - (i), (4) - (iv)$ (3) $(1) - (iii), (2) - (i), (3) - (ii), (4) - (iv)$ (4) $(1) - (iv), (2) - (iii), (3) - (ii), (4) - (i)$ 63. $The sol prepared by Bredig's Arc method is X and the charge of sol particles of it is q . X and q are respectively.$ (1) $Metal sol, -ve$ (2) $Metal sol, +ve$ (3) $Metal sulphide sol,-ve$ (4) $TiO_{2} sol, +ve$ 64. $If the value of \frac{1}{n} is equal to 1 in Freundlich adsorption isotherm, then \frac{x}{m} = (x = mass of absorbate, m = mass of the absorbent, p = pressure of the gas)$ (1) $\frac{K}{p}$ (2) $Kp$ (3) $K$ (4) $0$ 65. $Which of the following statements is/are not correct?(A) Adsorption is accompanied by decrease in enthalpy as well as decrease in entropy of the system.(B) Gases, which can react strongly with adsorbent show chemisorption.(C) When the value of the slope of the Freundlich isotherm is non-zero, adsorption is independent of pressure.(D) Gold number of potato starch is 0.15 .$ (1) $A, D$ (2) $B, C$ (3) $A, C$ (4) $C, D$ 66. $For micelle formation, which of the following statements are correct? (A) Micelle formation is an exothermic process. (B) Micelle formation is an endothermic process. (C) The entropy change is positive. (D) The entropy change is negative.$ (1) $A and D only$ (2) $A and C only$ (3) $B and C only$ (4) $B and D only$ 67. $The basic principle of Cottrell's precipitator is$ (1) $neutralisation of charge on colloidal particles$ (2) $scattering of light$ (3) $Le-Chatelier's principle$ (4) $peptisation.$ 68. $Which of the following is the most effective in causing coagulation of ferric hydroxide solution?$ (1) $KCl$ (2) $KNO_{3}$ (3) $K_{2} SO_{4}$ (4) $K_{3} (Fe (CN)_{6})$ 69. $Haemoglobinand gold sol are examples of:$ (1) $positivelyand negatively charged sols, respectively$ (2) $Positively charged sols$ (3) $Negatively charged sols$ (4) $Negatively and positively charged sols, respectively.$ 70. $The gold numbers of gelatin, haemoglobin and sodium acetate are 5 \times 10^{- 3}, 5 \times 10^{- 2} and 7 \times 10^{- 1}, respectively. The protective actions will be in the order$ (1) $Gelatin < haemoglobin < sodium acetate$ (2) $Gelatin > haemoglobin > sodium acetate$ (3) $Haemoglobin > gelatin > sodium acetate$ (4) $Sodium acetate > gelatin > haemoglobin$ 71. $Statements about Enzyme Inhibitor Drugs are given below : (A) There are Competitive and Non-competitive inhibitor drugs. (B) These can bind at the active sites and allosteric sites. (C) Competitive Drugs are allosteric site blocking drugs. (D) Non-competitive Drugs are active site blocking drugs. Choose the correct answer from the options given below:$ (1) $(A), (D) only$ (2) $(A), (C) only$ (3) $(A), (B) only$ (4) $(A), (B), (C) only$ 72. $According to hardy-schultz rule, Coagulation value or flocculation value \propto Fe (OH)_{3} sol is:$ (1) $K_{2} Cr O_{4} > K_{3} [Fe (CN)_{6}] > KN O_{3} > KBr = Al C l_{3}$ (2) $K_{3} [Fe (CN)_{6}] > K_{2} Cr O_{4} > KN O_{3} = KBr = AlC l_{3}$ (3) $K_{3} [Fe (CN)_{6}] < K_{2} Cr O_{4} < KN O_{3} = KBr = AlC l_{3}$ (4) $KN O_{3} > KBr = K_{2} Cr O_{4} > AlC l_{3} = K_{3} [Fe (CN)_{6}]$ 73. $Which one of the following statements is true?$ (1) $Saponification of oil yields a diol$ (2) $Drying of oil involves hydrolysis$ (3) $Addition of antioxidant to oil minimizes rancidity$ (4) $Refining of oil involves hydrogenation$ 74. $The correct statements about Zeolites are (I) They are good shape selective catalysts (II) They contain Al-O-Si framework (III) They are not found in nature (IV) They are used as catalysts for cracking hydrocarbons, in petrochemical industry$ (1) $I & II only$ (2) $II & III only$ (3) $III & IV only$ (4) $I, II & IV only$ 75. $Which property of colloids is not dependent on the charge on colloidal particles?$ (1) $Coagulation$ (2) $Electrophoresis$ (3) $Electro‐osmosis$ (4) $Tyndall effect$ 76. $Assertion (A) : Animal skins are colloidal in natureReason (R) : Animal skin has positively charged particles.$ (1) $Both (A) and (R) are correct and (R) is the correct explanation of (A)$ (2) $Both (A) and (R) are correct and (R) is not the correct explanation of (A)$ (3) $(A) is correct but (R) is incorrect$ (4) $(A) is incorrect but (R) is correct "$ 77. $The correct statement(s) about surface properties is(are)$ (1) $The critical temperatures of ethane and nitrogen are 563 K and 126 K, respectively. The adsorption of ethane will be more than that of nitrogen of same amount of activated charcoal at a given temperature.$ (2) $Cloud is an emulsion type of colloid in which liquid is dispersed phase and gas is dispersion medium.$ (3) $Adsorption is accompanied by decrease in enthalpy and decrease in entropy of the system.$ (4) $Brownian motion of colloidal particles does not depend on the size of the particles but depends on viscosity of the solution.$ 78. $2.0 g of activated charcoal is added to 100 mL of 0.5 M acetic acid (molar mass 60 g mol^{- 1}), shaken well and filtered. The concentration of solution is reduced to 0.4 M . How many grams of acetic acid is adsorbed on charcoal per gram?$ (1) $0.1$ (2) $0.2$ (3) $0.3$ (4) $0.15$ 79. $Freundlich adsorption isotherm fails at which of the following condition?$ (1) $High temperature$ (2) $Low temperature$ (3) $High pressure$ (4) $Low pressure$ 80. $The stability of a lyophobic colloid is due to$ (1) $adsorption of covalent molecules on the colloid$ (2) $the size of the particles$ (3) $the charge on the particles$ (4) $Tyndall effect.$ 81. $The colloidal solution used to treat stomach disorders is$ (1) $Silver sol$ (2) $Antimony sol$ (3) $Milk of magnesia$ (4) $Gold sol$ 82. $Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: The diameter of colloidal particles in solution should not be much smaller than wavelength of light to show Tyndall effect. Reason R: The light scatters in all directions when the size of particles is large enough. In the light of the above statements, choose the correct answer from the options given below:$ (1) $Both A and R are correct and R is the correct explanation of A$ (2) $A is true but R is false$ (3) $Both A and R are correct but R is NOT the correct explanation of A$ (4) $A is false but R is true$ 83. $Critical Micelle concentration for a soap solution is 1.5 \times 10^{- 4} mol L^{- 1} . Micelle formation is possible only when the concentration of soap solution in mol L^{- 1} is$ (1) $2.0 \times 10^{- 3}$ (2) $4.6 \times 10^{- 5}$ (3) $7.5 \times 10^{- 5}$ (4) $1.1 \times 10^{- 4}$ 84. $A 42.12% (w/v) solution of NaCl causes precipitation of a certain sol in 10 hours. The coagulating value of NaCl for the sol is [Given : Molar mass : Na = 23.0 g m o l^{- 1}; Cl = 35.5 g m o l^{- 1}]$ (1) $36 mmol L^{- l}$ (2) $36 mol L^{- 1}$ (3) $1440 m o l L^{- 1}$ (4) $1440 mmol L^{- 1}$ 85. $Which of the following is a correct statement ?$ (1) $Brownian motion destabilises sols.$ (2) $Any amount of dispersed phase can be added to emulsion without destabilising it.$ (3) $Mixing two oppositely charged sols in equal amount neutralises charges and stabilises colloids.$ (4) $Presence of equal and similar charges on colloidal particles provides stability to the colloidal solution$ 86. $For precipitating Fe (OH)_{3} sol, the best precipitating agent is$ (1) $Na_{2} SO_{4}$ (2) $Cr (OH)_{3}$ (3) $Al (OH)_{3}$ (4) $Na_{3} (Fe (CN)_{6})$ 87. $The electrolyte having maximum flocculation value for Agl / Ag^{+} sol is$ (1) $Na_{2} S$ (2) $Na_{3} PO_{4}$ (3) $NaCl$ (4) $Na_{2} SO_{4}$ 88. $Methylene blue, from its aqueous solution, is adsorbed on activated charcoal at 25° C. For this process, the correct statement is$ (1) $The adsorption requires activation at 25°C.$ (2) $The adsorption is accompanied by a decreases in enthalpy.$ (3) $The adsorption increases with increase of temperature.$ (4) $The adsorption is irreversible.$ 89. $Flocculation value for A s_{2} S_{3} sol by HCl is 30 m mole L^{- 1} . Calculate mass of H_{2} S O_{4} required in gram for 250 mL sol. Multiply your answer with 100.$ 90. $When 200 mL of 0.2 M acetic acid is shaken with 0.6 g of wood charcoal, the final concentration of acetic after adsorption is 0.1 M. The mass of acetic acid adsorbed per garm of carbon is_____g.$