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Which of the following aqueous solutions has the lowest freezing point?
(A) 0.2 m NaCl
(B) 0.2 m CaCl2 (C) 0.2 m H2SO4 (D) 0.2 m NH3
(E) 0.2 m Al(NO3)3 Answer and Explanation:Freezing point of a pure solvent depends on the amount of solute that gets dissolved in it. In order to determine which solution has the lowest freezing point, we need to look at the molality as well as whether the solute is ionic or covalent. Since the molality is equal for all of the answer choices, we need to look at what kind of solutes are present. Choice A: NaCl is ionic since it has a metal and a nonmetal. NaCl dissociates into 2 ions: Na+ and Cl – Choice B: CaCl2 is ionic since it has a metal and a nonmetal. CaCl2 dissociates into 3 ions: one Ca 2+ and two Cl- ionsChoice C: H2SO4 is a strong acid, and dissociates into 3 ions: two H+ and one SO4 2-Choice D: NH3 is a covalent compound since it is composed of 2 nonmetals, and therefore doesn’t dissociate when it is in waterChoice E: Al(NO3)3 is an ionic compound and will dissociate into 4 ions when it dissolves in water: one Al3+ and 3 NO3 – ions. Thus, since Al(NO3)3 dissociates into the most ions, the solution with it will have lowest freezing point.
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Which of the following aqueous solutions will have the – colligative properties like depression in freezing point and elevation in boiling point directly depends over no. of particles of solute.but freezing point &boiling point are not colligative properties.so in this question lowest freezing point is of 0.1 M Al 2 (SO 4) 3 due to greater no. of particles & hence greater deppression in freezing point takes place.and in case of boiling point ,valueSolved: Which aqueous solution would you expect to have the lowest freezing point: (a) 0.10 molal glucose, C6H12O6, or (b) 0.10 molal NaCl…Thus, as the concentration increases, the value of the properties would as well increase. For the case of freezing point, the solution which would contain more solute particles or highest concentration would be the solution that will have the lowest freezing point.
Which aqueous solution would you expect to have the lowest – Answer: (d)1%CaCl2. Explanation: Depression in freezing point is a colligative property which depend upon the amount of the solute. where, = change in freezing point. i= vant hoff factor = freezing point constant. m = molality (a) 1% glucose: For non electrolytes like glucose, vant hoff factor is 1.D)higher boiling point and a lower freezing point 3.Compared to a 2.0 M aqueous solution of NaCl at 1 atmosphere, a 3.0 M aqueous solution of NaCl at 1 atmosphere has a A)higher freezing point and a lower boiling point than water B)higher freezing point and a higher boiling point than water C)lower freezing point and a higher boiling point than3.24 g of H g (N O 3 ) 2 (m o l a r m a s s = 3 2 4) dissolved in 1000 g of water constitutes a solution having a freezing point of − 0. 0 5 5 8 o C while 21.68 g of H g C l 2 (Molar mass = 271) in 2000 g of water constitutes a solution with a freezing point of − 0. 0 7 4 4 o C.
Which of the following aqueous solutions has the lowest – Depression in freezing point is a colligative property which depends upon the amount of the solute. Δ T f = i × k f × m. where T f is the change in freezing point, i is Vant Hoff factor, m is molality and k is freezing point constant. 1% glucose will have Vant Hoff factor 1, 1% sucrose will have Vant Hoff factor 1.The freezing point depressions of aqueous solutions A, B, and C are -2.3 C, -I.ZC, and -4.1' C, respectively. Predict the order of the boiling point elevations for these solutions, from lowest to highest. Explain your ranking. lutions would have an osmotic pressure most similar to that of a 4.0 m C12H22011 solution?Freezing point = 0 – 17.6 = -17.6 oC A solution that contains 55.0 g of ascorbic acid (Vitamin C) in 250 g of water freezes at – 2.34°C. Calculate the approximate molar mass (in units of g/mol) of the solute. Kf of water is 1.86°C/m.