Ch.12 - SolutionsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Solution: Which of the following solutions will have the lowest freezing point? Input the appropriate letter.A. 35.0 g of C3H8O in 250.0 g of ethanol (C2H5OH)B. 35.0 g of C4H10O in 250.0 g of ethanol (C2H5OH)C. 35.0 g of C2H6O2 in 250.0 g of ethanol (C2H5OH)

Problem

Which of the following solutions will have the lowest freezing point? Input the appropriate letter.

A. 35.0 g of C3H8O in 250.0 g of ethanol (C2H5OH)

B. 35.0 g of C4H10O in 250.0 g of ethanol (C2H5OH)

C. 35.0 g of C2H6O2 in 250.0 g of ethanol (C2H5OH)

Solution

We’re being asked to determine the solution will have the lowest freezing point.


Recall that the freezing point of a solution is lower than that of the pure solvent and the change in freezing point (ΔT­f) is given by:


ΔTf=Tf, pure solvent-Tf, solution


The change in freezing point is also related to the molality of the solution:


ΔTf=imKf


where: 

i = van’t Hoff factor

m = molality of the solution (in m or mol/kg)

Kf = freezing point depression constant (in ˚C/m)


The solution with the highest change in freezing point (ΔTf) will be the solution with the lowest freezing point

Solution BlurView Complete Written Solution