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
Sections
Solutions, Molarity and Intermolecular Forces
Henry's Law
Calculate Molarity
Mass Percent
Molality
Mole Fraction
The Colligative Properties
Additional Practice
Making Solutions
Freezing Point Depression
Colloid
Additional Guides
ppm
The Freezing Point Depression (IGNORE)
Boiling Point Elevation

Molality (m) represents the amount of solute dissolved per kilogram of solvent. 

Understanding Molality

Example #1:

Molality is depicted as moles of solute per kilograms of solvent.

 

Concept #1: Ionic molality or osmolality represents the molality of dissolved ions in a solution. 

 

Example #2:

A solution is prepared by dissolving 43.0 g potassium chlorate, KClO3, in enough water to make 100.0 mL of solution. If the density of the solution is 1.760 g/mL, what is the molality of KClO3 in the solution? MW of KClO3 is 122.55 g/mol. 

Molality Calculations

Example #3:

If the molality of glucose, C6H12O6, in an aqueous solution is 2.56 what is the molarity? Density of the solution is 1.530 g/mL.

 

Example #4:

What is the ionic molality of nitrate ions in 0.305 m lead (IV) nitrate, Pb(NO3)4?.

 

Practice: What is the mass percent of NH3 of a 1.25 m aqueous solution of NH3?