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: Nicotine, extracted from tobacco leaves, is a liquid completely miscible with water at temperatures below  60°C. What is the molality of nicotine (a covalent substance) in an aqueous solution that sta

Solution: Nicotine, extracted from tobacco leaves, is a liquid completely miscible with water at temperatures below  60°C. What is the molality of nicotine (a covalent substance) in an aqueous solution that sta

Problem

Nicotine, extracted from tobacco leaves, is a liquid completely miscible with water at temperatures below  60°C. What is the molality of nicotine (a covalent substance) in an aqueous solution that starts to freeze at -0.450°C? (Note that the Kf for water is 1.86 °C m -1)

a) 2.42

b) 0.0336

c) 4.13

d) 29.7

e) 0.242

 

Solution

We’re being asked to find the molality of a solution when nicotine is dissolved in water. When calculating the freezing point of a solution, we’re going to use the equation for Freezing Point Depression.


∆Tf = change in freezing point = Tf pure solvent –Tf solution
Kf = freezing point depression constant
i = van' t Hoff factor of the solute = no. of ions
m = molality


Determine the required values for the Freezing Point Depression equation:

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