Chemistry_Class-12_Ch-1_Solution_Topic-6_ Boiling Point And Freezing Point 1 / 30 1) Pressure cooker reduces cooking time for food because A) Heat is more evenly distributed in the cooking space B) Boiling point of water involved in cooking is increased C) The higher pressure inside the cooker crushes the food material D) Cooking involves chemical changes helped by a rise in temperature 2 / 30 2) When a substance is dissolved in a solvent, the vapour pressure of solvent decreases. It brings A) A decrease in boiling point of solution B) An increase in boiling point of the solution C) A decrease in freezing point of the solution D) An increase in freezing point of the solution 3 / 30 3) If for a sucrose solution elevation in boiling point is 0.1°C then what will be the boiling point of NaCl solution for same molal concentration A) ) 0.1°C B) 0.2°C C) 0.08°C D) 0.01°C 4 / 30 4. The molal boiling point constant for water is 0.513° C kg mol-1 . When 0.1 mole of sugar is dissolved in 200mL of water, the solution boils under a pressure of one atmosphere at A) 100.513°C B) 100.0513°C C) 100.256° C D) 101.025° C 5 / 30 5. The temperature, at which the vapour pressure of a liquid becomes equal to the atmospheric pressure is known as A) Freezing point B) ) Boiling point C) Absolute temperature D) None of these 6 / 30 6) The elevation in boiling point of a solution of 13.44 g of CuCl2, in 1kg of water using the following information will be (Molecular weight of CuCl2=134.4 and Kb= 0.52 K molal-1) Assume CuCl2 a strong electrolyte A) 0.16 B) 0.05 C) 0.1 D) 0.1 7 / 30 7. When 10 g of a non-volatile solute is dissolved in 100 g of benzene, it raises boiling point by 1°C then molecular mass of the solute is (Kb for benzene = 2.53 K m-1) A) 223 g/mole B) 233 g/mole C) 243 g/mole D) 253 g/mole 8 / 30 8. An aqueous solution containing 1g of urea boils at 100.25°C. The aqueous solution containing 3 g of glucose in the same volume will boil at (Molecular weight of urea and glucose are 60 and 180 respectively) A) 100.75°C B) 100.5°C C) 100.25°C D) 100°C 9 / 30 9. When common salt is dissolved in water A) Melting point of the solution increases B) Boiling point of the solution increases C) Boiling point of the solution decreases D) Both melting point and boiling point decreases 10 / 30 10) If 0.5 g of a solute (molar mass 100 g /mol ) in 25 g of solvent elevates the boiling point by 1 K , the molar boiling point constant of the solvent is A) 2 B) ৪ C) 5 D) 0.5 11 / 30 11. The molal elevation or ebullioscopic constant for water is A) 1.86 K molality⁻¹ B) 526 K molality⁻¹ C) 55.5 K molality D) 0.52 K molality⁻¹ 12 / 30 12) 58.5 g of NaCl and 180 g of glucose were separately dissolved in 1000 mL of water. Identify the correct statement regarding the elevation of boiling point (b.pt.) of the resulting solutions A) NaCl solution will show higher elevation of b.pt. B) Glucose solution will show higher elevation of b.pt. C) Both the solutions will show equal elevation of b.pt. D) The b.pt. of elevation will be shown by neither of the solutions 13 / 30 13. The boiling point of 0.2 mol kg -1 solution of X in water is greater than equimolal solution of Y in water. Which one of the following statements is true in this case …. A) Molecular mass of X is greater than the molecular mass of Y B) Molecular mass of X is less than the molecular mass of Y C) Y is undergoing dissociation in water while X undergoes no change D) X is undergoing dissociation in water 14 / 30 14. A liquid can exist only A) Between triple point and critical point B) At any temperature above melting point C) Between melting point and critical point D) Between boiling and melting points 15 / 30 15. Boiling point of chloroform was raised by 0.323 K, when 0.5143 g of anthracene was dissolved in 35 g of chloroform. Molecular mass of anthracene is …. A) 79.42 g/mol B) 132.32 g/mol C) 177.42 g/mol D) 242.32 g/mol 16 / 30 16. The boiling point of water (100°C) becomes 100.52°C, if 3 g of a non-volatile solute is dissolved in 200mL of water. The molecular weight of solute is(Kb for water is 0.6 K kg mol A) 12.2 g mol⁻¹ B) 15.4 g mol ⁻¹ C) 17.3 g mol ⁻¹ D) ) 20.4 g mol ⁻¹ 17 / 30 17) The boiling points for aqueous solutions of sucrose and urea are same at constant temperature. If 3 g of urea is dissolved in its 1 litre solution, what is the weight of sucrose dissolved in its 1 litre solution [Urea-60 g/mole, sucrose 342 g/mole A) 3.0 g B) 17.1 g C) 6.0 g D) 34.2 g 18 / 30 18. The unit of ebullioscopic constant is A) K kg mol⁻¹ or K (molality)⁻¹ B) Mol kg K-1 or K-1 (molality) C) kg mol-1 K-1 or K-1 (molality)-1 D) K mol kg -1or K(molality) 19 / 30 19. During the evaporation of liquid A) The temperature of the liquid will rise B) The temperature of the liquid will fall C) May rise or fall depending on the nature D) The temperature remains unaffected 20 / 30 20. 1g of a non-volatile non-electrolyte solute is dissolved in 100g of two different solvents A and B whose ebullioscopy constants are in the ratio of 1:5. The ratio of the elevation A) 1:5 B) 10:1 C) 1:0.2 D) 5:1 21 / 30 21) Which one of the following statements is FALSE A) The correct order of osmotic pressure for 0.01 m aqueous solution of each compound is BaCl2 > KCI > CH3COOH> sucrose B) The osmotic pressure (𝝅) of a solution is given by the equation 𝝅 =MRT where M is the molarity of the solution C) Raoult's law states that the vapour pressure of a component over a solution is proportional to its mole fraction D) Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression 22 / 30 22) 1% solution of Ca(NO3)2 has freezing point A) 0°C B) Less than 0°C C) Greater than 0°C D) None of the above 23 / 30 23) A solution of urea (mol. mass 60g mol-1 ) boils at 100.18°C at the atmospheric pressure. If Kf and Kb for water are 1.86 and 0.512 K kg mol-1 respectively the above solution will freeze at A) - 6.54°C B) 6.54°C C) 0.654°C D) - 0.654°C 24 / 30 24) The molar freezing point constant for water is 1.86°C kg mole. If 342 g of cane-sugar (C12H22O11) are dissolved in 1000 g of water, the solution will freeze at A) -1.86°C B) 1.86°C C) -3.92°C D) 2.42°C 25 / 30 25) KBr is 80% dissociated in aqueous solution of 0.5 m concentration (Given Kf for water 1.86 K kg mol-1 ). The solution freezes at A) 271.326 K B) 272 K C) 270.5 K D) 268.5 K 26 / 30 26) After adding a solute freezing point of solution decreases to - 0.186. Calculate ∆Tb if Kf = 1.86 and Kb = 0.521 A) 0.521 B) 0.0521 C) 0.0186 D) 1.86 27 / 30 27) During depression of freezing point in a solution the following are in equilibrium A) Liquid solvent, solid solvent B) Liquid solvent, solid solute C) Liquid solute, solid solute D) Liquid solute, solid solvent 28 / 30 28. Which of the following aqueous molal solution have highest freezing point A) Urea B) Barium chloride C) Potassium bromide D) Aluminium sulphate 29 / 30 30) What should be the freezing point of aqueous solution containing 17 gm of C2H5OH in 1000 gm of water (water Kf = 1.86 0 C kg mol-1) A) -0.69°C B) -0.34°C C) 0.0°C D) 0.34°C 30 / 30 29) Which will show maximum when concentration is 0.1M depression in freezing point A) NaCl B) Urea C) Glucose D)Potassium sulphate Your score isThe average score is 0% 0% Exit
