Solutions PYQs Set 11 (PDF)

Set 11 of 14 · Questions 301-330 of 419

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Solutions · Set 11 (Q301-330)
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301. $A solution containing 62 g ethylene glycol in 250 g water is cooled to -10ºC. If K_{f} for water is 1.86 K kg m o l^{-1}, the amount of water (in g) separated as ice is:$ (1) $16$ (2) $32$ (3) $48$ (4) $64$ 302. $Match List - I with List - II. List - I (A) Solution of chloroform and acetone (B) Solution of ethanol and water (C) Solution of benzene and toluene (D) Solution of acetic acid in benzene List - II (I) Minimum boiling azeotrope (II) Dimerizes (III) Maximum boiling azeotrope (IV) Δ V_{mix} = 0 Choose the correct answer from the options given below:$ (1) $(A)-(III), (B)-(I), (C)-(IV), (D)-(II)$ (2) $(A)-(III), (B)-(IV), (C)-(I), (D)-(II)$ (3) $(A)-(II), (B)-(I), (C)-(IV), (D)-(III)$ (4) $(A)-(II), (B)-(IV), (C)-(I), (D)-(III)$ 303. $and are the vapour pressure of pure liquid components, and , respectively of an ideal binary solution. If represents the mole fraction ofcomponent , the total pressure of the solution will be$ (1) $p_{A} + x_{A} (p_{B} - p_{A})$ (2) $p_{A} + x_{A} (p_{A} - p_{B})$ (3) $p_{B} + x_{A} (p_{B} - p_{A})$ (4) $p_{B} + x_{A} (p_{A} - p_{B})$ 304. $The freezing point of benzene decreases by 0.45ºC when 0.2 g of acetic acid is added to 20 g of benzene. If acetic acid associates to form a dimer in benzene, percentage association of acetic acid in benzene will be : (K_{f} for benzene = 5.12 K kg m o l^{-1})$ (1) $80.4%$ (2) $74.6%$ (3) $94.6%$ (4) $64.6%$ 305. $A solution of urea (mol. mass 56 g m o l^{- 1}) boils at 100. 18 C at the atmospheric pressure. If K_{f} and K_{b} for water are 1.86 and 0.512 K kg m o l^{- 1} respectively, the above solution will freeze at$ (1) $0. 654 C$ (2) $- 0.654 C$ (3) $6. 54 C$ (4) $- 6.54 C$ 306. $Boiling point of a 2% aqueous solution of a nonvolatile solute A is equal to the boiling point of 8% aqueous solution of a non-volatile solute B. The relation between molecular weights of A and B is.$ (1) $M_{A} = 4 M_{B}$ (2) $M_{b} = 4 M_{A}$ (3) $M_{A} = 8 M_{B}$ (4) $M_{B} = 8 M_{A}$ 307. $If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water (∆ T_{f}), when 0.01 mole of sodium sulphate is dissolved in 1 kg of water, is (K_{f} = 1.86 K kg mol^{-1})$ (1) $0.0372 K$ (2) $0.0558 K$ (3) $0.0744 K$ (4) $0.0186 K$ 308. $A graph of vapour pressure and temperature for three different liquids X, Y and Z is shown below:The following inferences are made:(A) Intermolecular force of attraction of X > Y (B) Intermolecular force of attraction of X < Y .(C) Intermolecular force of attraction of Z<X.$ (1) $A and C$ (2) $A and B$ (3) $B only$ (4) $B and C$ 309. $Which of the following salt has the same value of vant’s Hoff factor (i) as that of K_{3} [Fe (CN)_{6}] ?$ (1) $N a_{2} S O_{4}$ (2) $A l (N O_{3})_{3}$ (3) $A l_{2} (S O_{4})_{3}$ (4) $N a C l$ 310. $Which one of the following graphs accurately represents the plot of partial pressure of vs its mole fraction in a mixture of acetone and at constant temperature?$ (1) (2) (3) (4) 311. $In the depression of freezing point experiment A. Vapour pressure of the solution is less than that of pure solvent B. Vapour pressure of the solution is more than that of pure solvent C. Only solute molecules solidify at the freezing point D. Only solvent molecules solidify at the freezing point$ (1) $A and D only$ (2) $B and C only$ (3) $A and C only$ (4) $A only$ 312. $Which of the following properties will change when system containing solution 1 will become solution 2?$ (1) $Molar heat capacity$ (2) $Concentration$ (3) $Gibbs free energy$ (4) $Density$ 313. $Two 5 molal solutions are prepared by dissolving a non-electrolyte non-volotatile solute separately in the solvents X and Y. The molecular weights of the solvents are M_{X} and M_{Y}, respectively where M_{X} = \frac{3}{4} M_{Y} . The relative lowering of vapour pressure of the solution in X is "m" times that of the solution in Y. Given that the number of moles of solute is very small in comparison to that of solvent, the value of "m" is :$ (1) $\frac{4}{3}$ (2) $\frac{3}{4}$ (3) $\frac{1}{2}$ (4) $\frac{1}{4}$ 314. $Which of the following statements about the composition of the vapour over an ideal 1 : 1 molar mixture of benzene and toluene is correct? Assume that the temperature is constant at 2 5^{o} C . (Given, vapour pressure data at 2 5^{o} C, benzene = 12.8 k P a, toluene = 3.85 k P a)$ (1) $The vapour will contain equal amounts of benzene and toluene.$ (2) $Not enough information is given to make a prediction.$ (3) $The vapour will contain a higher percentage of benzene.$ (4) $The vapour will contain a higher percentage of toluene.$ 315. $Liquids A and B form an ideal solution in the entire composition range. At 350 K, the vapor pressures of pure A and pure B are 7 \times 1 0^{3} Pa and 12 \times 1 0^{3} Pa, respectively. The composition of the vapor in equilibrium with a solution containing 40 mole percent of A at this temperature is :$ (1) $x_{A} = 0.28 ; x_{B} = 0.72$ (2) $x_{A} = 0.76 ; x_{B} = 0.24$ (3) $x_{A} = 0.37 ; x_{B} = 0.63$ (4) $x_{A} = 0.4 ; x_{B} = 0.6$ 316. $For the solution of the gases w, x, y and z in water at 298 K, the Henrys law constants (K_{H}) are 0.5, 2, 35 and 40 kbar, respectively. The correct plot for the given data is:$ (1) (2) (3) (4) 317. $What is the molarity of H_{2} S O_{4} solution, that has a density 1.84 g / cc at 3 5^{o} C and contains 98% by weight?$ (1) $18.4 M$ (2) $18 M$ (3) $4.18 M$ (4) $8. 14 M$ 318. $The osmotic pressure of a dilute solution is 7 \times 10^{5} Pa at 273 K . Osmotic pressure of the same solution at 283 K is______\times 10^{4} Nm^{- 2} .$ 319. $0.004 M K_{2} S O_{4} solution is isotonic with 0.01 M glucose solution. Percentage dissociation of K_{2} S O_{4} is_____(Nearest integer)$ 320. $An aqueous solution of volume 300 c m^{3} contains 0. 63 g of protein. The osmotic pressure of the solution at 300 K is 1. 29 mbar. The molar mass of the protein is g m o l^{- 1} . Given : R = 0.083 L_{ba r} K^{- 1} m o l^{- 1}$ 321. $The vapors pressure vs. temperature curve for a solution solvent system is shown below. The boiling point of the solvent is_____°C.$ 322. $The vapour pressure of 30% (w/v), aqueous solution of glucose is________mm Hg at 25°C. [Given: The density of 30% (w/v), aqueous solution of glucose is 1.2 g c m^{- 3} and vapour pressure of pure water is 24 mm Hg.] (Molar mass of glucose is 180 g m o l^{- 1})$ 323. $If the degree of dissociation of aqueous solution of weak monobasic acid is determined to be 0.3, then the observed freezing point will be_____% higher than the expected/theoretical freezing point. (Nearest integer).$ 324. $'x' g of molecular oxygen (O_{2}) is mixed with 200 g of neon (Ne). The total pressure of the non-reactive mixture of O2 and Ne in the cylinder is 25 bar. The partial pressure of Ne is 20 bar at the same temperature and volume. The value of 'x' is_____. [Given: Molar mass of O2 = 32 g mol^{- 1} . Molar mass of Ne = 20 g mol^{- 1}]$ 325. $The vapour pressures of A and B at are 90mmHg and 15mmHg respectively. If A and B are mixed such that the mole fraction of A in the mixture is 0.6, then the mole fraction of B in the vapour phase is . The value of is ___(Nearest integer)$ 326. $Solution of 12 g of non-electrolyte (A) prepared by dissolving it in 1000 mL of water exerts the same osmotic pressure as that of 0. 05 M glucose solution at the same temperature. The empirical formula of A is C H_{2} O. The molecular mass of A is________g. (Nearest integer)$ 327. $A solution containing 2. 5 x 1 0^{- 3} kg of a solute dissolved in 75 x 1 0^{- 3} kg of water boils at 373.535 K. The molar mass of the solute is______g m o l^{- 1} . [nearest integer] (Given: K_{b} (H_{2} O) = 0.52 K Kg m o l^{- 1}, boiling point of water = 373.15K)$ 328. $If the boiling points of two solvents X and Y (having same molecular weights) are in the ratio 2: 1 and their enthalpy of vaporizations are in the ratio 1:2, then the boiling point elevation constant of X is m times the boiling point elevation constant of Y. The value of m is (nearest integer).$ 329. $1.46 g of a biopolymer dissolved in a 100 mL water at 300 K exerted an osmotic pressure of 2.42 \times 1 0^{- 3} bar. The molar mass of the biopolymer is ____\times 1 0^{4} g m o l^{- 1} (Round off to the Nearest Integer) [Use: R = 0.083 L ba r m o l^{- 1} K^{- 1}]$ 330. $Solid Lead nitrate is dissolved in 1 litre of water. The solution was found to boil at 100.15°C. When 0.2 mol of NaCl is added to the resulting solution, it was observed that the solution froze at -0.8° C The solutbility product of P b C l_{2} formed is______x 1 0^{- 6} at 298 K. (Nearest integer) Given : K_{b} = 0.5 K kg m o l^{- 1} and K_{f} = 1.8 kg m o l^{- 1} . Assume molality to be equal to molarity in all cases.$