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Topic 1: Stoichiometric Relationships

1.1 Introduction to the Particulate Nature of Matter & Chemical Change
Essential Idea:
  • Physical and chemical properties depend on the ways in which different atoms combine.
  • Atoms of different elements combine in fixed ratios to form compounds, which have different properties from their component elements.
  • Mixtures contain more than one element and/or compound that are not chemically bonded together and so retain their individual properties.
  • Mixtures are either homogeneous or heterogeneous.
Applications & Skills:
  • Deduction of chemical equations when reactants and products are specified.
  • Application of the state symbols (s), (l), (g) and (aq) in equations.
  • Explanation of observable changes in physical properties and temperature during changes of state.
Nature of Science:
  • Making quantitative measurements with replicates to ensure reliability—definite and multiple proportions.
PPT: 1.1 Matter & Chemical Changes
Classifying Elements, Mixtures & Compounds
Video Lesson: Elements, Mixtures & Compounds
Simulation Lab: States of Matter
Virtual Lab: Physical vs Chemical Properties
Video Lesson: Balancing Chemical Equations Basics
Simulation Activity: Balancing Equations
Video Lesson: Atom Economy
American Chemical Society: What is Green Chenistry?
EPA: Green Chemistry
1.2 The Mole Concept
Essential Idea:
  • The mole makes it possible to correlate the number of particles with the mass that can be measured.
  • The mole is a fixed number of particles and refers to the amount, n, of substance.
  • Masses of atoms are compared on a scale relative to 12C and are expressed as relative atomic mass (Ar) and relative formula/molecular mass (Mr).
  • Molar mass (M) has the units g/mol.
  • The empirical formula and molecular formula of a compound give the simplest ratio and the actual number of atoms present in a molecule respectively.
Applications & Skills:
  • Calculation of the molar masses of atoms, ions, molecules and formula units.
  • Solution of problems involving the relationships between the number of particles, the amount of substance in moles and the mass in grams.
  • Interconversion of the percentage composition by mass and the empirical formula.
  • Determination of the molecular formula of a compound from its empirical formula and molar mass.
  • Obtaining and using experimental data for deriving empirical formulas from reactions involving mass changes.
Nature of Science:
  • Concepts—the concept of the mole developed from the related concept of “equivalent mass” in the early 19th century.
PPT: The Mole Concept
TED: How Big is a Mole?
Video: The Mole Concept
Video: Mole Calculations
Mole Calculation Practice Problems
Percent Composition Practice
Khan Academy: Determining Empirical Formulas
Empricial Formula Practice
1.3 Reacting Masses & Volumes
Essential Idea:
  • Mole ratios in chemical equations can be used to calculate reacting ratios by mass and gas volume.
  • Reactants can be either limiting or excess.
  • The experimental yield can be different from the theoretical yield.
  • Avogadro’s law enables the mole ratio of reacting gases to be determined from volumes of the gases.
  • The molar volume of an ideal gas is a constant at specified temperature and pressure.
  • The molar concentration of a solution is determined by the amount of solute and the volume of solution.
  • A standard solution is one of known concentration.
Applications & Skills:
  • Solution of problems relating to reacting quantities, limiting and excess reactants, theoretical, experimental and percentage yields.
  • Calculation of reacting volumes of gases using Avogadro’s law.
  • Solution of problems and analysis of graphs involving the relationship between temperature, pressure and volume for a fixed mass of an ideal gas.
  • Solution of problems relating to the ideal gas equation.
  • Explanation of the deviation of real gases from ideal behaviour at low temperature and high pressure.
  • Obtaining and using experimental values to calculate the molar mass of a gas from the ideal gas equation.
  • Solution of problems involving molar concentration, amount of solute and volume of solution.
  • Use of the experimental method of titration to calculate the concentration of a solution by reference to a standard solution.
Nature of Science:
  • Making careful observations and obtaining evidence for scientific theories—Avogadro's initial hypothesis.
PPT: Stoichiometry, Limiting Reactants & Percentage Yield
Video Lesson: Limiting & Excess Reactants
Khan Academy: Limiting Reactants
Limiting Reactant Practice
Stoichiometry Practice
Video Lesson: Percentage Yield
Percentage Yield Practice
PPT: Gas Laws
Music Video: Rock Me Avogadro with Gas Laws
Gas Law Practice Problems
Lab Video: Molar Mass of Butane
Video: Gay Lussac's Law with Examples
Video: Reacting Volumes of Gas
pHet Simulation: Gas Laws
Khan Academy: Ideal Gas Law
Video: Gay Lussac's Law with Examples
PPT: Solutions
Solution Practice Problems
Titration of a Standard Solution - Watch to write procedure and make data table.