Surface Chemistry PYQs Set 2 (PDF)

Set 2 of 9 · Questions 31-60 of 248

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Surface Chemistry · Set 2 (Q31-60)
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31. $Which of the following statements about colloids is False?$ (1) $When silver nitrate solution is added to potassium iodide solution a negatively charged colloidal solution is formed.$ (2) $Freezing point of colloidal solution is lower than true solution at same concentration of a solute.$ (3) $Colloidal particles can pass through ordinary filter paper.$ (4) $When excess of electrolyte is added to colloidal solution, colloidal particle will be precipitated.$ 32. $Which property of colloids is not dependent on the charge on colloidal particles?$ (1) $Coagulation$ (2) $Electrophoresis$ (3) $Both (a) and (b)$ (4) $Tyndall effect$ 33. $Which of the following is not an example of heterogeneous catalytic reaction ?$ (1) $Ostwald’s process$ (2) $Haber’s process$ (3) $Combustion of coal$ (4) $Hydrogenation of vegetable oils$ 34. $Given below are two statements : Statement I: Emulsions of oil in water are unstable and sometimes they separate into two layers on standing. Statement II :For stabilisation of an emulsion, excess of electrolyte is added. choose the most appropriate answer from the options given below :$ (1) $Both Statement I and Statement II are correct.$ (2) $Both Statement I and Statement II are incorrect.$ (3) $Statement I is correct but Statement II is incorrect$ (4) $Statement I is incorrect but Statement II is correct.$ 35. $The coagulating power of electrolytes having ions Na^{+}, Al^{3 +} and Ba^{2 +} for arsenic sulphide sol increases in the order:$ (1) $Al^{3 +} < Ba^{2 +} < Na^{+}$ (2) $Na^{+} < Ba^{2 +} < Al^{3 +}$ (3) $Ba^{2 +} < Na^{+} < Al^{3 +}$ (4) $Al^{3 +} < Na^{+} < Ba^{2 +}$ 36. $During the adsorption of krypton on activated charcoal at low temperature,$ (1) $Δ H > 0 and Δ S < 0$ (2) $Δ H < 0 and Δ S < 0$ (3) $Δ H > 0 and Δ S > 0$ (4) $Δ H < 0 and Δ S > 0$ 37. $Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : In expensive scientific instruments, silica gel is kept in watch-glasses or in semipermeable membrane bags. Reason (R) : Silica gel adsorbs moisture from air via adsorption, thus protects the instrument from water corrosion (rusting) and / or prevents malfunctioning. choose the correct answer from the options given below :$ (1) $(A) is false but (R) is true$ (2) $(A) is true but (R) is false$ (3) $Both (A) and (R) are true and (R) is the correct explanation of (A)$ (4) $Both (A) and (R) are true but (R) is not the correct explanation of (A)$ 38. $The most effective coagulating agent for antimony sulphide sol is$ (1) $K_{2} SO_{4}$ (2) $NH_{4} Cl$ (3) $Al_{2} (SO_{4})_{3}$ (4) $K_{4} (Fe (CN)_{6})$ 39. $Which of the following ion has greater coagulating power for negatively charged sol?$ (1) $Fe (CN)_{6}^{4 -}$ (2) $PO_{4}^{3 -}$ (3) $Ba^{2 +}$ (4) $Al^{3 +}$ 40. $Which one of the following statements is not correct?$ (1) $The value of equilibrium constant is changed in the presence of a catalyst in the reaction at equilibrium.$ (2) $Enzymes catalyse mainly biochemical reactions.$ (3) $Coenzymes increase the catalytic activity of enzyme.$ (4) $Catalyst does not initiate any reaction.$ 41. $The process of converting a precipitate into colloidal solution is known as$ (1) $Dialysis$ (2) $Peptization$ (3) $Electrophoresis$ (4) $Flocculation$ 42. $Which one of the following characteristics is associated with adsorption?$ (1) $∆ G and ∆ H are negative but ∆ S is positive.$ (2) $∆ G and ∆ S are negative but ∆ H is positive.$ (3) $∆ G is negative but ∆ H and ∆ S are positive.$ (4) $∆ G, ∆ H and ∆ S all are negative.$ 43. $For coagulation of arsenioussulphide sol, which one of the following salt solution will be most effective ?$ (1) $BaCl_{2}$ (2) $AlCl_{3}$ (3) $NaCl$ (4) $Na_{3} P O_{4}$ 44. $Colloidal solution of gold is in different colours like red, purple, blue and golden because of$ (1) $variable oxidation states of gold.$ (2) $size difference in the particles of gold.$ (3) $presence of impurities.$ (4) $difference in the concentration of gold particles.$ 45. $On which of the following properties does me coagulating power of an ion depend?$ (1) $The magnitude of the charge on the ion alone$ (2) $Size of the ion alone$ (3) $Both magnitude and sign of the charge on the ion$ (4) $The sign of charge on the ion alone$ 46. $Hydrogenation of vegetable oils in presence of finely divided nickel as catalyst, the reaction is$ (1) $enzyme catalysed reaction$ (2) $liquid catalysed reaction$ (3) $heterogeneous catalysis$ (4) $homogeneous catalysis.$ 47. $A colloidal system has particles of which of the following size?$ (1) $1 0^{- 9} m to 1 0^{- 12} m$ (2) $1 0^{- 6} m to 1 0^{- 9} m$ (3) $1 0^{- 4} m to 1 0^{- 10} m$ (4) $1 0^{- 5} m to 1 0^{- 7} m$ 48. $The following statements relate to the adsorption of gases on a solid surface. Identify the incorrect statement among them:$ (1) $On adsorption decrease in surface energy appears as heat$ (2) $Enthalpy of adsorption is negative$ (3) $On adsorption, the residual forces on the surface are increased$ (4) $Entropy of adsorption is negative$ 49. $What happens when a lyophilic sol is added to a lyophobic sol?$ (1) $Film of lyophobic sol is formed over lyophilic sol.$ (2) $Lyophilic sol is dispersed in lyophobic sol.$ (3) $Film of lyophilic sol is formed over lyophobic sol.$ (4) $Lyophobic sol is coagulated$ 50. $When a sulphur sol is evaporated sulphur is obtained. On mixing with water sulphur sol is not formed. The sol is$ (1) $lyophilic$ (2) $reversible$ (3) $hydrophobic$ (4) $hydrophilic.$ 51. $In which of the following, the sol is not correctly matched with respect to its charge? I. Al_{2} O_{3} \cdot x \cdot H_{2} O sol; + ve sol II. Starch sol; +ve sol III. TiO_{2} sol; -ve sol IV. Methylene blue sol; +ve sol The correct answer is$ (1) $I, IV$ (2) $I, III$ (3) $II, III$ (4) $II, IV$ 52. $Ferric chloride is applied to stop bleeding because -$ (1) $FeCl_{3} reacts with the constituents of blood which is a positively charged sol.$ (2) $Blood absorbs FeCl_{3} and forms a complex.$ (3) $Cl^{-} ions cause coagulation of blood.$ (4) $Fe^{3 +} ions coagulate blood which is a negatively charged sol.$ 53. $Which one of the following statements is incorrect about enzyme catalysis?$ (1) $Enzymes are mostly proteinous in nature.$ (2) $Enzyme action is specific.$ (3) $Enzymes are denatured by ultraviolet rays and at high temperature.$ (4) $Enzymes are least reactive at optimum temperature.$ 54. $The Langmuir adsorption isotherm is deduced using the assumption$ (1) $the adsorption sites are equivalent in their ability to adsorb the particles$ (2) $the heat of adsorption varies with coverage$ (3) $the adsorbed molecules interact with each other$ (4) $the adsorption takes place in multilayers.$ 55. $A colloidal solution is subjected to an electric field then colloidal particles move towards anode. The amount of electrolytes of BaCl_{2}, AlCl_{3} and NaCl required to coagulate the given colloid is in the order$ (1) $NaCl > BaCl_{2} > AlCl_{3}$ (2) $BaCl_{2} < AlCl_{3} < NaCl$ (3) $AlCl_{3} = NaCl = BaCl_{2}$ (4) $AlCl_{3} > BaCl_{2} > NaCl$ 56. $Which one of the following method is commonly used method for destruction of colloid?$ (1) $Dialysis$ (2) $Condensation$ (3) $Filteration by animal membrane$ (4) $By adding electrolyte$ 57. $Match List-I with List-II. List-I (A) I Negatively charged sol (B) Macromolecular colloid (C) Positively charged sol (D) Cheese List-II (I) F e_{2} O_{3} . x H_{2} O (II) CdS sol (III) Starch (IV) a gel Choose the correct answer from the options given below:$ (1) $(A) - (II), (B) - (III), (C) - (IV), (D) - (I)$ (2) $(A) - (II), (B) - (I), (C) - (III), (D) - (IV)$ (3) $(A) - (II), (B) - (III), (C) - (I), (D) - (IV)$ (4) $(A) - (I), (B) - (III), (C) - (II), (D) - (IV)$ 58. $Which of the following can form ionic micelles in water?$ (1) $Starch molecules$ (2) $sodium lauryl sulphate$ (3) $Iodine molecules$ (4) $S_{8} molecules$ 59. $2.0 g of H_{2} gas is adsorbed on 2.5 g of platinum powder at 300 K and 1 bar pressure. The volume of the gas adsorbed per gram of the adsorbent is ________mL.(Given : R = 0.083 L bar K^{- 1} m o l^{- 1})$ 60. $The number of incorrect statement/s from the following is/are_______A. Water vapours are adsorbed by anhydrous calcium chloride. B. There is a decrease in surface energy during adsorption. C. As the adsorption proceeds, AH becomes more and more negative. D. Adsorption is accompanied by decrease in$