Surface Chemistry PYQs Set 1 (PDF)

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Surface Chemistry · Set 1 (Q1-30)
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1. $For a linear plot of log(x/m) versus log p in a Freundlich adsorption isotherm, which of the following statements is correct? (k and n are constants)$ (1) $1/n appears as the intercept$ (2) $Only 1/n appears as the slope.$ (3) $log (1/n) appears as the intercept.$ (4) $Both k and 1/n appear in the slope term.$ 2. $A sol of AgI is prepared by mixing equal volumes of 0.1 M AgNO_{3} and 0.2 MKI, which of the following statement is correct?$ (1) $Sol obtained is a positive sol with Ag^{+} adsorbed on AgI.$ (2) $Sol obtained is a positive sol with K^{+} adsorbed on AgI.$ (3) $Sol obtained is a negative sol with I^{-} adsorbed on AgI.$ (4) $Sol obtained is a negative sol with NO_{3}^{-} adsorbed on AgI.$ 3. $Which of the following salt solutions would coagulate the colloid solution formed when F e C l_{3} is added to NaOH solution, at the fastest rate?$ (1) $10 mL of 0.2 mol d m^{- 3} A 1 C 1_{3}$ (2) $10 mL of 0.1 mol d m^{- 3} N a_{2} S O_{4}$ (3) $10 mL of 0.1 mol d m^{- 3} C a_{3} (P O_{4})_{2}$ (4) $10 mL of 0.15 mol d m^{- 3} C a C l_{2}$ 4. $Which one of the following is correct for the adsorption of a gas at a given temperature on a solid surface?$ (1) $ΔH > 0,ΔS > 0$ (2) $ΔH > 0,ΔS < 0$ (3) $ΔH < 0,ΔS < 0$ (4) $ΔH < 0,ΔS > 0$ 5. $The coagulation of 200 ml of a positive colloid took place when 0.73 g of HCl was added to it without changing the volume much. The flocculation value of HCl for the colloid is$ (1) $1000$ (2) $0.365$ (3) $200$ (4) $100$ 6. $Which from following catalyst is used in decomposition of KClO_{3} ?$ (1) $Platinized asbestos$ (2) $Fe-Cr catalyst$ (3) $Ni$ (4) $MnO_{2}$ 7. $Which of the following is not a favourable condition for physical adsorption?$ (1) $High pressure$ (2) $Low temperature$ (3) $High temperature$ (4) $Higher critical temperature of adsorbate$ 8. $Rate of physical adsorption increases with$ (1) $decrease in temperature$ (2) $decrease in pressure$ (3) $increase in temperature$ (4) $decrease in surface area.$ 9. $Which of the following is an example of a multi molecular colloid?$ (1) $Sulphur sol$ (2) $Starch sol$ (3) $Natural rubber sol$ (4) $Soap sol$ 10. $At the critical micelle concentration (CMC) the surfactant molecules$ (1) $associate$ (2) $dissociate$ (3) $decompose$ (4) $become completely soluble$ 11. $Which of the following colloids cannot be easily coagulated?$ (1) $Multimolecular colloids$ (2) $Irreversible colloids$ (3) $Lyophobic colloids$ (4) $Macromolecular colloids$ 12. $Among the following, the surfactant that will form micelles in aqueous solution at the lowest molar concentration at ambinent condition is:$ (1) $C H_{3} (C H_{2})_{15} N^{+} (C H_{3})_{3} B r^{-}$ (2) $C H_{3} (C H_{2})_{11} OSO_{3}^{-} N a^{+}$ (3) $C H_{3} (C H_{2})_{6} C O O^{-} N a^{+}$ (4) $C H_{3} (C H_{2})_{11} N^{+} (C H_{3})_{3} B r^{-}$ 13. $Which one of the following characteristics is not correct for physical adsorption?$ (1) $Adsorption on solids is reversible$ (2) $Adsorption increases with increase in temperature$ (3) $Adsorption is spontaneous$ (4) $Both enthalpy and entropy of adsorption are negative.$ 14. $Match the following List - I (Dispersed Phase - Dispersion medium) (A) Solid - Liquid (B) Liquid - Liquid (C) Solid-Gas (D) Liquid - Solid List - II (Type of colloid) (I) Gel (II) Aerosol (III) Sol (IV) Emulsion The correct answer is$ (1) $A-II, B-III, C-I, D-IV$ (2) $A-III, B-IV, C-II, D-I$ (3) $A-III, B-IV, C-I, D-II$ (4) $A-I, B-III, C-IV, D-II$ 15. $Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Amongst He, Ne, Ar and Kr; 1 g of activated charcoal adsorbs more of Kr, Reason R : The critical volume V_{c} (c m^{3} m o l^{- 1}) and critical pressure P_{c} (atrn) is highest for Krypton but the compressibility factor at critical point Z_{c} is lowest for Krypton. choose the correct answer from the options given below.$ (1) $A is true but R is false$ (2) $A is false but R is true$ (3) $Both A and R are true but R is NOT the correct explanation of A$ (4) $Both A and R are true and R is the correct explanation A$ 16. $Lyophilic sols are more stable than lyophobic sols because :$ (1) $there is a strong electrostatic repulsion between the negatively charged colloidal particles.$ (2) $the colloidal particles have positive charge.$ (3) $the colloidal particles have no charge.$ (4) $the colloidal particles are solvated.$ 17. $A hard substance mells at high temperature andis an insulator in both solid and in molten state. This solid is most likely to be a / an :$ (1) $Ionic solid$ (2) $Molecular solid$ (3) $Metallic solid$ (4) $Covalent solid$ 18. $Among the following, the INCORRECT statement about colloids is:$ (1) $They can scatter light.$ (2) $They are larger than small molecules and have high molar mass.$ (3) $The osmotic pressure of a colloidal solution is of higher order than the true solution at the same concentration.$ (4) $The range of diameters of colloidal particles is between 1 and 1000 nm.$ 19. $Colloidal solution commonly used in the treatment of skin disease is$ (1) $colloidal gold$ (2) $colloidal antimony$ (3) $colloidal sulphur$ (4) $colloidal silver.$ 20. $Incorrect statement for Tyndall effect is :-$ (1) $The refractive indices of the dispersed phase and the dispersion medium differ greatly in magnitude.$ (2) $The diameter of the dispersed particles is much smaller than the wavelength of the light used.$ (3) $During projection of movies in the cinemas hall, Tyndall effect is noticed.$ (4) $It is used to distinguish a true solution from a colloidal solution.$ 21. $The most effective coagulating agent among the options for Sb_{2} S_{3} sol is$ (1) $Na_{2} SO_{4}$ (2) $Al_{2} (SO_{4})_{3}$ (3) $CaCl_{2}$ (4) $NH_{4} Cl$ 22. $Adsorption of a gas follows Freundlich adsorption isotherm. If x is the mass of the gas adsorbed on mass m of the adsorbent, the correct plot of \frac{x}{m} versus p is:$ (1) (2) (3) (4) 23. $Which of the following cations will have minimum flocculation value for arsenic sulphide sol?$ (1) $Na^{+}$ (2) $Mg^{2 +}$ (3) $Ca^{2 +}$ (4) $Al^{3 +}$ 24. $Among the colloids cheese (C), milk (M) and smoke (S), the correct combination of the dispersed phase and dispersion medium, respectively is :-$ (1) $C : liquid in solid; M : liquid in solid; S : solid in gas$ (2) $C :liquid in solid; M : liquid in liquid; S : solid in gas$ (3) $C : solid in liquid; M : liquid in liquid; S : gas in solid$ (4) $C :solid in liquid; M : solid in liquid; S : solid in gas$ 25. $Given below are two statements (S-I and S-II) S-I: Scattering of light by dispersed particles of colloidal system is known as Tyndall effect. S-II: The diameter of the dispersed particles should not be much smaller than the wavelength of the light used. Choose the most appropriate answer from the options given below.$ (1) $Both S-I and S-II are correct$ (2) $S-I is correct but S-II is incorrect$ (3) $Both S-I and S-II are incorrect$ (4) $S-I is incorrect but S-II is correct$ 26. $Which one of the following statements is correct for adsorption of solutes on solids in solutions?$ (1) $The extent of adsorption increases with an increase in temperature.$ (2) $The extent of adsorption decreases with an increase of surface area of the adsorbate.$ (3) $The extent of adsorption decreases with an increase in temperature.$ (4) $The extent of adsorption does not depend on the amount of the solute in solution.$ 27. $Which of the following gases is readily adsorbed by solid adsorbent?$ (1) $Cl_{2}$ (2) $N_{2}$ (3) $O_{2}$ (4) $H_{2}$ 28. $Adsorption of gases on solid surface is generally exothermic because$ (1) $enthalpy is positive$ (2) $entropy decreases$ (3) $entropy increases$ (4) $free energy increases$ 29. $20 mL of 0.5 M NaCl is required to coagulate 200 mL of As_{2} S_{3} solution in 2 hours. The coagulating value of NaCl is .$ 30. $The number of colloidal systems from the following, which will have 'liquid' as the dispersion medium, is . Gem stones, paints, smoke, cheese, milk, hair cream, insecticide sprays, froth, soap lather$