MCQs on Freezing Point of the Solvent
1. Which one of the following gases has the lowest value of Henry’s law constant?
(a) N2
(b) He
(c) H2
(d) CO2
Answer:::: (d)
2. If 10ml of 0.1M aqueous solution of NaCl is divided into 1000 drops of equal volume. What will be the concentration of one drop?
(a) 0.01M
(b) 0.10M
(c) 0.001M
(d) 0.0001M
Answer:::: (b)
3. A 0.5 molal solution of ethylene glycol in water is used as a coolant in a car. If the freezing point constant of water be 1.86oC per mole, the mixture shall freeze at
(a) 0.93oC
(b) -0.93oC
(c) 1.86oC
(d) -1.86oC
Answer:::: (b)
4. Which statement is true for a solution of 0.020M H2SO3?
(a) 2 litre of the solution contains 0.020 mole of SO42-
(b) 2 litre of the solution contains 0.080 mole of H3O+
(c) 1 litre of the solution contains 0.020 mole of H3O+
(d) None of these
Answer:::: (b)
5. A 500g toothpaste sample has 0.2g fluoride concentration. What is the concentration of F in terms of ppm level?
(a) 250
(b) 300
(c) 400
(d) 1000
Answer:::: (c)
6. If at a certain temperature the vapour pressure of pure water is 25 mm Hg and that of a very dilute aqueous urea solution is 24.5mm Hg, the molality of the solution is
(a) 0.02
(b) 1.2
(c) 1.11
(d) 0.08
Answer:::: (c)
7. Which of the following 0.10m aqueous solutions will have the lowest freezing point?
(a) Al2(SO4)3
(b) C6H12O6
(c) KCl
(d) C12H22O11
Answer:::: (a)
8. The amount of urea to be dissolved in 500 cc of water (K = 1.86oC mol-1) to produce a depression of 0.186oC in the freezing point is
(a) 9g
(b) 6g
(c) 3g
(d) 0.3g
Answer:::: (c)
9. The empirical formula of a nonelectrolyte is CH2O. A solution containing 6g of the compound exerts the same osmotic pressure as that of 0.05M glucose solution at the same temperature, The molecular formula of the compound is
(a) C2H4O2
(b) C3H6O3
(c) C5H10O5
(d) C4H8O4
Answer:::: (d)
10. The molar mass of the solute sodium hydroxide obtained from the measurement of the osmotic pressure of its aqueous solution at 27oC is 25gmol-1. Therefore its ionization solution at 27oC is 25 g mol-1. Therefore its ionization percentage in this solution is
(a) 75
(b) 60
(c) 80
(d) 70
Answer:::: (b)
