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9., , 10,, 11., 12., 13., , 4., , 1, 15., , 18., , DILUTE SOLUTION, , , , For a dilute solution, Raoult’s law states that ;, , {a) the lowering of vapour pressure is equal to the mole fraction of solute, , (b) the relative lowering of vapour pressure is equal to the mole fraction of solute, , f 7 o ae lowering of vapour pressure is proportional to the amount of solute in solution, he vapour pressure of the solution is equal to the mole fraction of solvent, , The solubility of a specific non-volatile salt is 4 ¢ in 100 g of water at 25°C. If 2.0 g, 4.0 g and, , 6.0 g of the salt added of 100 g of water at 25°C, in system X,¥ and Z. The vapour pressure, , would be in the order:, , (a) X-< LZ (b) X>Y>7Z (O Z>X-¥ (d) X=¥=Z, , The boiling point of C,H,, CH,OH, C,H NH, and C,H.NO, are 80°C, 65°C, 184°C and, , 212°C respectively, Which will show highest vapour pressure al room temperature :, , (a) C,H, (b) CH,OH {c) CglsNH2 (@) C,H.NO,, , 6.0 g of urea (molecular mass = 60) was dissolved in 9.9 moles of water, If the vapour, , pressure of pure warer is P°, the vapour pressure of solution is:, , (a) 0.10 P° (b) 1,10 P* (c) 0.90 P° {d) 0.99 P*, , An ideal solution was found to have a vapour pressure of 80 torr when the mole fraction of a, , non-volatile solu yas 0.2. What would be the vapour pressure of the pure solvent at the, , same temperature?, , (a) 64 torr {b) 80 torr (c) 100 torr (d) 400 torr, , ressure of an aqueous solution of sucrose at 373 K is found to be 750 mm Hg. The, , T t ‘olution at the same temperature will be :, , (a) 0.26 (b) 0.73 (c) 0.74 (d) 0.039, , Estimate the lowering of vapour pressure due to the solute (glucose) in a 1.0 M aqueous, , ution ar 100°C, , fa) 10 torr (b) 18 torr {c) 13.45 torr (d) 24 torr, , Calculate the mass of non-volatile solute having molecular mass 40, which should be dissolved, , in rm octane to reduce its vapour pressure to 80R5:, , (a) « g (b) 58 {c) 106.2 ¢ {d) None of these, , Equal mass of a solute are dissolved in equal mass of two solvents A and B and formed very, , lative lowering of vapour pressure for the solution B has twice the, dM, are the molecular mass, , , , , , , , , , , , dilute solution, The re r, relative lowering of vapour pressure for the solution A. If M4 an, , A and B respectively, then:, (b) My =2*M, (c) My =4My (d) M, =2Mg, , o components A and B. A is more volatile than B, Le., Pa > Pp and also, mole fractions of components A in liquid and vapour phases, then:, {c) X,<¥a (d) Data insufficient, , 40) is 100 torr, while that-of pure, of a solution containing 208, , of solvents, (a) M, =M5, An ideal solution has tw, P2 > Pro HEX 4 and¥ are, , . Nae, (a) X, =Ya (b) X4>%n A, At 25°C, the vapour pressure of pure liquid A (mol. mass = ), liquid B is 40 torr, (mol. mass = 80). The vapour pressure at 25°C, , f ex and B is: ae, eee (b) 59.8 torr {c) 68 torr {d)