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Set 2 of 14 · Questions 31-60 of 419

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JEE Main Chemistry · Solutions · Set 2 (Q31-60)

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  1. 31.
    At 298 K, the mole percentage of in air is . Water is in equilibrium with air at a pressure of 10 atm. What is the mole fraction of in water at 298 K? ( for is )
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  2. 32.
    Solute ' ' dimerises in water to the extent of of ' ' in of water increases the boiling point by . The molar mass of ' ' is
    1. (1)52
    2. (2)65
    3. (3)26
    4. (4)13
  3. 33.
    18 g glucosse () is added to 178.2 g water. The vapor pressure of water (in torr) for this aqueous solution is.
    1. (1)76.0
    2. (2)752.4
    3. (3)759.0
    4. (4)7.6
  4. 34.
    of sugar was dissolved in water to produce of sugar syrup. The molality and mole fraction of sugar in the syrup are respectively ( )
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  5. 35.
    Assertion: Standard boiling point of a liquid is slightly higher than the normal boiling point.
    Reason: 1 bar pressure is slightly less than 1 atm pressure.
    1. (1)Assertion and Reason are correct statements and Reason is the correct explanation for Assertion.
    2. (2)Assertion and Reason are correct statement and Reason is not the explanation for Assertion.
    3. (3)Assertion is correct, Reason is incorrect.
    4. (4)Assertion is incorrect, Reason is correct.
  6. 36.
    The mixture that forms maximum boiling azeotrope is:
    1. (1)Water + Nitric acid
    2. (2)Ethanol + Water
    3. (3)Acetone + Carbon disulphide
    4. (4)Heptane + Octane
  7. 37.
    Which of the following pair of solutions is isotonic?
    1. (1) and
    2. (2) and
    3. (3) and
    4. (4) and
  8. 38.
    The empirical formula of a nonelectrolyte is . A solution containing of the compound exerts the same osmotic pressure as that of glucose solution. The molecular formula of the compound is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  9. 39.
    The vapour pressure of pure liquids and are 450 and of at respectively. If the total vapour pressure of the mixture is of , the composition of the mixture in the solution is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  10. 40.
    What would be the molality of 20% (mass/mass) aqueous solution of Kl ? (molar mass of Kl = 166 g )
    1. (1)1.08
    2. (2)1.35
    3. (3)1.48
    4. (4)1.51
  11. 41.
    Molecules of benzoic acid dimerise in benzene. ‘w’ g of the acid dissolved in 30 g of benzene shows a depression in freezing point equal to 2 K. If the percentage association of the acid to form dimer in the solution is 80 then w is : (Given that K kg Molar mass of benzoic acid = 122 g )
    1. (1)2.4 g
    2. (2)1.0 g
    3. (3)1.5 g
    4. (4)1.8 g
  12. 42.
    According to Raoult’s law, the relative lowering of vapour pressure for a solution is equal to
    1. (1)mole fraction of solute
    2. (2)mole fraction of solvent
    3. (3)moles of solute
    4. (4)moles of solvent.
  13. 43.
    What happens to freezing point of benzene when small quantity of napthalene is added to benzene?
    1. (1)Increases
    2. (2)Remains unchanged
    3. (3)First decreases and then increases
    4. (4)Decreases
  14. 44.
    The boiling point of 0.2 mol solution of in water is greater than equimolal solution of in water. Which one of the following statements is true in this case?
    1. (1)Molecular mass of is less than the molecular mass of
    2. (2) is undergoing dissociation in water while undergoes no change.
    3. (3) is undergoing dissociation in water.
    4. (4)Molecular mass of is greater than the molecular mass of Y
  15. 45.
    Which of the following aqueous solutions has the highest freezing point?
    1. (1)
    2. (2) Sucrose
    3. (3)
    4. (4)
  16. 46.
    Of the following 0.10 aqueous solutions, which one will exhibit the largest freezing point depression?
    1. (1)KC1
    2. (2)
    3. (3)
    4. (4)
  17. 47.
    At 80ºC, the vapour pressure of pure liquid 'A' is 520 mm Hg and that of pure liquid 'B' is 1000 mm Hg. If a mixture solution of 'A' and 'B' boils at 80ºC and 1 atm pressure, the amount of 'A' in the mixture is (1 atm = 760 mm Hg)
    1. (1)34 mol percent
    2. (2)48 mol percent
    3. (3)50 mol percent
    4. (4)52 mol percent
  18. 48.
    Given below are two statements:
    Statement I : Gallium is used in the manufacturing of thermometers.
    Statement II : A thermometer containing gallium is useful for measuring the freezing point of brine solution.
    In the light of the above statements, choose the correct answer from the options given below :
    1. (1)Both Statement I and Statement II are true
    2. (2)Statement I is false but Statement II is true
    3. (3)Both Statement I and Statement II are false
    4. (4)Statement I is true but Statement II is false
  19. 49.
    A liquid mixture is an ideal solution, if
    (i) It obeys ideal gas equation
    (ii) It obeys Raoult's law at all concentrations
    (iii) Solute - solute, solute - solvent and solvent - solvent interactions are similar
    1. (1)(i) only
    2. (2)(i), (ii) only
    3. (3)(ii), (iii) only
    4. (4)(iii) only
  20. 50.
    Liquid A and B form an ideal solution. The vapour pressures of pure liquids and are 350 and 750 mm Hg respectively at the same temperature. If and are the mole fraction of and in solution while and are the mole fraction of and in vapour phase, then,
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  21. 51.
    The freezing point depression constant of benzene is 5.12 . The freezing point depression for the solution of molality 0.078 m containing a non-electrolyte solute in benzene is (rounded off upto two decimal places) :
    1. (1)0.80 K
    2. (2)0.40 K
    3. (3)0.60 K
    4. (4)0.20 K
  22. 52.
    of sodium hydroxide (molar mass ) is dissolved in little quantity of water and the solution is diluted up to . What is the molarity of the resulting solution?
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  23. 53.
    Calculate the relative lowering of vapour pressure if the vapour pressure of benzene and vapour pressure of solution of non volatile solute in benzene are and respectively at same temperature.
    1. (1)0.078
    2. (2)0.175
    3. (3)0.061
    4. (4)0.092
  24. 54.
    The vapour pressure of benzene at a certain temperature is 640 mm of Hg. A non‐volatile and non‐electrolyte solid, weighing 2.175 is added to 39.08 of benzene. The vapour pressure of the solution is 600 mm of Hg. What is the molecular weight of solid substance?
    1. (1)69.5
    2. (2)59.6
    3. (3)49.50
    4. (4)79.8
  25. 55.
    Molality of solution (density ) is______ .
  26. 56.
    The oxygen dissolved in water exerts a partial pressure of in the vapour above water. The molarsolubility of oxygen in water is (Round off to the Nearest Integer).[Given : Henry's law constantfor
    Density of water with dissolved oxygen
  27. 57.
    A solute a dimerizes in water. The boiling point of a molar solution of is . The
    percentage association of is
    (Round off to the Nearest integer)
    [Use : for water
    Boiling point of water
  28. 58.
    When 1 g each of compounds AB and are dissolved in 15 g of water separately, they increased the boiling point of water by 2.7 K and 1.5 K respectively. The atomic mass of A (in amu) is (Nearest integer)
    (Given: Molal boiling point elevation constant is )
  29. 59.
    The osmotic pressure of blood is 7.47 bar at 300 K. To inject glucose to a patient intravenously, it has to be isotonic with blood. The concentration of glucose solution in is _____(Molar mass of glucose = 180 g R = 0.083 L bar ) (Nearest integer)
  30. 60.
    At 27°C, a solution containing 2.5 g of solute in 250.0 mL of solution exerts an osmotic pressure of 400 Pa. The molar mass of the solute is____g (Nearest integer)(Given : R = 0.083 L bar )