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

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?