Solutions PYQs Set 4 (PDF)

Set 4 of 14 · Questions 91-120 of 419

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Solutions · Set 4 (Q91-120)
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91. $Which of the following does not belong to an ideal solution?$ (1) $Δ H_{mix} = 0$ (2) $Δ V_{mix} = 0$ (3) $Obeys Raoult's law over the entire range of concentration$ (4) $Does not obey Raoult's law$ 92. $The molal elevation constant is the ratio of elevation in boiling point to$ (1) $molarity$ (2) $molality$ (3) $mole fraction of solute$ (4) $mole fraction of solvent$ 93. $During osmosis, flow of water through a semipermeable membrane is$ (1) $from solution having lower concentration only$ (2) $from solution having higher concentration only$ (3) $from both sides of semipermeable membrane with equal flow rates$ (4) $from both sides of semipermeable membrane with unequal flow rates.$ 94. $When 10^{- 3} M solution of glucose in water, freezes at - 0.0186^{\circ} C, then at what temperature 10^{- 3} M solution of NaCl will freeze?$ (1) $0^{\circ} C$ (2) $0.186^{\circ} C$ (3) $- 0.186^{\circ} C$ (4) $- 0.0372^{\circ} C$ 95. $A camphor sample melts at 176^{\circ} C . K_{f} for camphor is 40 K kg mol^{- 1} . A solution of 0.02 g of a hydrocarbon in 0.8 g of camphor melts at 156.77^{\circ} C . The hydrocarbon is made up of 92.3 % of carbon. What is the molecular formula of the hydrocarbon?$ (1) $C_{6} H_{6}$ (2) $C_{12} H_{12}$ (3) $C_{4} H_{4}$ (4) $C_{8} H_{8}$ 96. $The van’t Hoff factor for 0.1 M Ba (N O_{3})_{2} solution is 2.74. The degree of dissociation is :$ (1) $91.3%$ (2) $87%$ (3) $100%$ (4) $74%$ 97. $Which one of the following 0.06M aqueous solutions has lowest freezing point?$ (1) $A l_{2} (S O_{4})_{3}$ (2) $C_{6} H_{12} O_{6}$ (3) $KI$ (4) $K_{2} S O_{4}$ 98. $1 g of a non-volatile non-electrolyte solute is dissolved in 100 g of two different solvents A and B whose ebullioscopic constants are in the ratio of 1 : 5. The ratio of the elevation in their boiling points, \frac{Δ Tb ( A )}{Δ Tb ( B )}, is :$ (1) $5:1$ (2) $10:1$ (3) $1:5$ (4) $1:02$ 99. $On mixing, heptane and octane form an ideal solution. At 373 K, the vapour pressures of the two liquid components (heptane and octane) are 105 kPa and 45 kPa respectively. Vapour pressure of the solution obtained by mixing 25.0 g of heptane and 35 g of octane will be (molar mass of heptane = 100 g m o l^{-1} and of octane = 114 g m o l^{-1})$ (1) $72.0 kPa$ (2) $36.1 kPa$ (3) $96.2 kPa$ (4) $144.5 kPa$ 100. $What is the molality of a solution containing 200 mg of urea (molar mass = 60 g mol^{- 1}) dissolved in 40 g of water?$ (1) $0.0825$ (2) $0.825$ (3) $0.498$ (4) $0.0013$ 101. $Benzene and toluene form nearly ideal solutions. At 20ºC, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20 ºC for a solution containing 78 g of benzene and 46 g of toluene in torr is:$ (1) $50$ (2) $25$ (3) $37.5$ (4) $53.5$ 102. $The vapour pressure of pure CCl_{4} (molar mass = 154 g (mol^{- 1}) and SnCl_{4} () molar mass (= 170 g mol^{- 1}) at 25^{\circ} C are 115.0 and 238.0 torr respectively. Assuming ideal behaviour, calculate the total approximate vapour pressure in torr of a solution containing 10 g of CCl_{4} and 15 g of SnCl_{4} .$ (1) $185.85$ (2) $190.0$ (3) $180.7$ (4) $182.1$ 103. $What is the mole fraction of the solute in a 1.00 aqueous solution?$ (1) $1.770$ (2) $0.0354$ (3) $0.0177$ (4) $0.177$ 104. $The vapour pressure of pure water is 23 mmHg . The vapour pressure of an aqueous solution, which contains 10 mass per cent of solute ' A' having molecular weight 50 is$ (1) $0.003 atm$ (2) $34.5 atm$ (3) $22 atm$ (4) $0.028 atm$ 105. $An aqueous solution is 1.00 molal in K I . Which change will cause the vapour pressure of the solution to increase?$ (1) $Addition of N a C l$ (2) $Addition of N a_{2} S O_{4}$ (3) $Addition of 1.00 molal KI$ (4) $Addition of water$ 106. $If 500 mL of CaCl_{2} solution contains 3.01 \times 10^{22} chloride ions, molarity of the solution will be$ (1) $0.05 M$ (2) $0.01 M$ (3) $0.1 M$ (4) $0.02 M$ 107. $20 mL of 0.1 MHCl is added to the 30 mL of 0.1 M NaOH . To this solution extra 50 mL of water was added. What is the molarity of the final solution formed?$ (1) $0.1 M$ (2) $0.01 M$ (3) $0.5 M$ (4) $0.05 M$ 108. $Given below are two statements: Statement I: The Henry's law constant K_{H} is constant with respect to variations in solution's concentration over the range for which the solution is ideally dilute. Statement II: K_{H} does not differ for the same solute in different solvents. In the light of the above statements, choose the correct answer from the options given below$ (1) $Statement I is false but Statement II is true$ (2) $Both Statement I and Statement II are false$ (3) $Statement I is true but Statement II is false$ (4) $Both Statement I and Statement II are true$ 109. $At T (K), 2 moles of liquid A and 3 moles of liquid B are mixed. The vapour pressure of ideal solution formed is 320 mm Hg. At this stage, one mole of A and one mole of B are added to the solution. The vapour pressure is now measured as 328.6 mm Hg. The vapour pressure (in mm Hg) of A and B are respectively:$ (1) $400,300$ (2) $600,400$ (3) $300,200$ (4) $500, 200$ 110. $After adding non-volatile solute freezing point of water decreases to - 0.186^{\circ} C . Calculate Δ T_{b} if K_{f} = 1.86 K kg mol^{- 1} and K_{b} = 0.521 K kg mol^{- 1}$ (1) $0.0521 K$ (2) $0.0186 K$ (3) $0.521 K$ (4) $1.86 K$ 111. $Which of the following conditions are correct for real solutions showing negative deviation from Raoult's law?$ (1) $Δ H_{Mix} < 0; Δ V_{Mix} > 0$ (2) $Δ H_{Mix} > 0; Δ V_{Mix} > 0$ (3) $Δ H_{Mix} > 0; Δ V_{Mix} < 0$ (4) $Δ H_{Mix} < 0; Δ V_{Mix} < 0$ 112. $The Van’t Hoff factor i for acompound which undergoes dissociation in one solvent and association in other solvent is respectively$ (1) $less than one and greater than one$ (2) $less than one and less than one$ (3) $greater than one and less than one$ (4) $greater than one and greater than one.$ 113. $In countries nearer to polar region, the roads are sprinkled with CaCl_{2} . This is$ (1) $to minimise the snow fall$ (2) $to minimise pollution$ (3) $to minimise the accumulation of dust on the road$ (4) $to minimise the wear and tear of the roads.$ 114. $A solution of two miscible liquids showing negative deviation from Raoult's law will have :$ (1) $increased vapour pressure, increased boiling point$ (2) $increased vapour pressure, decreased boiling point$ (3) $decreased vapour pressure, decreased boiling point$ (4) $decreased vapour pressure, increased boiling point$ 115. $if O .l M solution ofglucose and 0.1 M solution of urea are placed on two sides of the semipermeable membrane to equal heights, then it will be correct to say that$ (1) $there will be no net movement across the membrane$ (2) $glucose will flow towards glucose solution$ (3) $urea will flow towards glucose solution$ (4) $water will flow from urea solution to glucose.$ 116. $For which among the following equimolar aqueous solutions, van't Hoff factor has the lowest value?$ (1) $Aluminium chloride$ (2) $Potassium sulphate$ (3) $Ammonium chloride$ (4) $Urea$ 117. $When 12.2 g of benzoic acid is dissolved in 100g of water, the freezing point of solution was found to be - 0.93° C (K_{b} (H_{2} O) = 1.86 K kg mol^{- 1}) . The number (n) of benzoic acid molecules associated (assuming 100% association) is:$ 118. $The elevation in boiling point for 1 molal solution of non-volatile solute A is 3K. The depression in freezing point for 2 molal solution of A in the same solvent is 6 K. The ratio of K_{b} and K_{f} i.e., K_{b} / K_{f} is 1 : X. The value of X is [nearest integer]$ 119. $A 1 molal K_{4} Fe (CN)_{6} solution has a degree ofdissociation of 0.4 . Its boiling point is equal to that of another solution which contains 18.1 weight percent of a non-electrolytic solute A . The molar mass of A is u . (Round off tothe Nearest Integer). [Density of water (= 1.0 g cm^{- 3})$ 120. $A solution of H_{2} SO_{4} is 31.4 % H_{2} SO_{4} by mass and has a density of 1.25 g / mL . The molarity of the H_{2} SO_{4} solution is_______ M (nearest integer) [Given molar mass of H_{2} SO_{4} = 98 g mol^{- 1}]$