Elevation of boiling point and depression of freezing point

37 questions on Elevation of boiling point and depression of freezing point from the Solutions and Colligative Properties chapter: 7 NEET level, 16 JEE Main, 14 JEE Advanced. Each one opens with its answer and solution.

• The boiling point elevation constant of water is K_b = 0.52 K kg mol^-1. A solution of a non-volatile non-electrolyte in water has molality 0.50 mol kg^-1. By h... NEET level
• Four aqueous solutions, each of molality 0.10 mol kg^-1, are prepared. Assume that every electrolyte dissociates completely. Which solution has the highest free... NEET level
• Which of the following is the correct unit of the molal freezing point depression constant K_f? NEET level
• Glucose (molar mass 180 g mol^-1), 1.8 g, is dissolved in 100 g of water. Taking K_f = 1.86 K kg mol^-1, the depression in freezing point is NEET level
• When 3.0 g of a non-electrolyte is dissolved in 100 g of benzene, the freezing point falls by 1.28 K. Given K_f(benzene) = 5.12 K kg mol^-1, the molar mass of t... JEE Main level
• A solution is prepared by dissolving 12 g of urea (molar mass 60 g mol^-1) in 200 g of water. The normal boiling point of water is 100.00 degC and K_b = 0.52 K ... JEE Main level
• Ethylene glycol (molar mass 62 g mol^-1) is added to 1.00 kg of water so that the solution freezes at -9.3 degC. Take K_f = 1.86 K kg mol^-1 and treat ethylene ... JEE Main level
• A solute of molar mass 125 g mol^-1 (2.5 g) is dissolved in 50 g of a solvent. The boiling point of the solvent rises by 0.86 K. Calculate K_b of the solvent in... JEE Main level
• For a solvent of molar mass M (in g mol^-1), normal freezing point T_f (in K) and molar enthalpy of fusion Delta H_fus, which expression gives K_f in K kg mol^-... JEE Main level
• Estimate K_f of water from T_f = 273 K, molar mass 18 g mol^-1, Delta H_fus = 6000 J mol^-1 and R = 8.314 J mol^-1 K^-1, using K_f = (M R T_f^2)/(1000 Delta H_f... JEE Main level
• Consider dilute solutions of non-volatile non-electrolytes in a given solvent. Which of the following statements is/are correct? JEE Main level
• Two solutes P (molar mass 60 g mol^-1) and Q (molar mass 180 g mol^-1), both non-electrolytes, are dissolved separately, 6.0 g each, in 100 g of water. The rati... JEE Main level
• A solution contains 9.0 g of glucose (molar mass 180 g mol^-1) and 6.0 g of urea (molar mass 60 g mol^-1) in 500 g of water. Taking K_f = 1.86 K kg mol^-1 and b... JEE Advanced level
• A 10.0% by mass aqueous solution of sucrose (molar mass 342 g mol^-1, non-electrolyte) is cooled. Taking K_f = 1.86 K kg mol^-1, find the temperature (in degC, ... JEE Advanced level
• 0.40 mol of glucose is dissolved in 500 g of water (K_b = 0.52 and K_f = 1.86 K kg mol^-1; normal boiling point 100.00 degC). Which of the following is/are corr... JEE Advanced level
• 62 g of ethylene glycol (molar mass 62 g mol^-1) is dissolved in 500 g of water (K_f = 1.86 K kg mol^-1). The solution is cooled slowly to -7.44 degC and equili... JEE Advanced level
• A solvent X has normal boiling point 350 K, molar mass 100 g mol^-1 and Delta H_vap = 30.0 kJ mol^-1. Use K_b = (M R T_b^2)/(1000 Delta H_vap) (M in g mol^-1, D... JEE Advanced level
• The cryoscopic constant of a solvent is K_f = (M R T_f^2)/(1000 Delta H_fus) (M in g mol^-1). Which of the following statements is/are correct? JEE Advanced level
• 2.0 g of a non-electrolyte X dissolved in 80 g of water freezes at -0.465 degC. Using K_f = 1.86 and K_b = 0.52 K kg mol^-1 (normal boiling point of water 100.0... JEE Advanced level
• Solvent X has an unknown molal elevation constant. Dissolving 1.8 g of glucose (M =180 g mol^-1) in 50 g of X raises its boiling point by 0.40 K. A second solut... JEE Advanced level
• A 1.00 mol L^-1 aqueous glucose solution (molar mass 180 g mol^-1) has a density of 1.12 g mL^-1. Using K_f=1.86 K kg mol^-1, calculate the depression in freezi... JEE Advanced level
• The molal elevation constant K_b of a liquid depends on NEET level
• Liquid X has a normal boiling point of 350 K, molar mass 100 g mol^-1 and Delta_vapH=30.0 kJ mol^-1. Use K_b=(RT_b^2M_1)/(1000 Delta_vap)H (with M_1 in g mol^-1... JEE Advanced level
• Which of the following statements about colligative properties of dilute solutions are correct? JEE Main level
• 2.5 g of a non-volatile non-electrolyte dissolved in 50 g of benzene raises its boiling point by 0.85 K. Given K_b(benzene)=2.53 K kg mol^-1, find the molar mas... JEE Main level
• How many grams of ethylene glycol (molar mass 62 g mol^-1) must be dissolved in 1.00 kg of water so that the solution freezes at -10.0 degC? Use K_f=1.86 K kg m... JEE Main level
• The molal depression constant can be written K_f=(RT_f^2M_1)/(1000 Delta_fus)H with M_1 in g mol^-1 and Delta_fusH in J mol^-1. For water take T_f=273 K, M_1=18... JEE Main level
• A solution of 36 g glucose (M =180 g mol^-1) in 400 g of water is slowly cooled to -2.79 degC, and pure ice separates until the remaining liquid solution is in ... JEE Advanced level
• The SI-compatible unit of the molal depression constant K_f is NEET level
• 12 g of urea (molar mass 60 g mol^-1) is dissolved in 400 g of water. Taking K_f(water) = 1.86 K kg mol^-1 and the freezing point of water as 0 degC, the freezi... JEE Main level
• A 10% by mass aqueous solution of glucose (molar mass 180 g mol^-1) is heated at 1 atm. Taking K_b=0.52 K kg mol^-1, the boiling point of the solution is closes... JEE Main level
• Which of the following non-volatile, non-electrolyte aqueous solutions has the highest boiling point? NEET level
• Four aqueous solutions of non-electrolytes are prepared: (i) 4.5 g urea (M =60) in 150 g water, (ii) 9.0 g glucose (M =180) in 90 g water, (iii) 17.1 g sucrose ... JEE Main level
• A solution contains 0.30 mol of a non-volatile, non-dissociating solute in 500 g of water. Use K_f=1.86 K kg mol^-1 and K_b=0.52 K kg mol^-1 and treat the solut... JEE Advanced level
• An aqueous solution contains 27 g glucose (M =180), 9.0 g urea (M =60) and 17.1 g sucrose (M =342) in 250 g of water (all in g mol^-1). None of the solutes diss... JEE Advanced level
• 31 g of ethylene glycol (molar mass 62 g mol^-1, non-volatile) is dissolved in 500 g of water. With K_b=0.52 K kg mol^-1 for water and a normal boiling point of... JEE Main level
• A compound X has empirical formula C3H6O (empirical formula mass 58 g mol^-1). When 0.87 g of X is dissolved in 25.0 g of benzene (K_f=5.12 K kg mol^-1), the fr... JEE Advanced level