## Chem1 Moles, formulas and equations

The eight lessons in this unit cover atomic and molecular weights, the mole concept, and its applications to stoichiometric calculations involving formulas and equations. A considerable number of problems are included. It is the author's experience that many students who experience difficulty with these topics can benefit from a more detailed treatment of topics that are often passed over in conventional instruction; examples are net ionic equations, and recognizing decimal equivalents of integer ratios, which is important in understanding "simplest formula" calculations.

Note: this lesson set is included with the Chem1 Starter Set; there is no need to download it separately.

## Lesson summary

Each bulleted item is individually accessible through a 2-level menu.

Lesson 1 - Introduction to the mole concept

• What is a mole?
• Visualizing the mole
• Numerical problems involving Avogadro's number

Lesson 2 -Formulas

• How to write and read them
• Molar mass
• Calculations based on formulas

Lesson 3 - Empirical formulas from experiment

• True formulas vs. empirical formulas
• Formulas and mole ratios
• Formuilas from mass composition
• problem - composition of a hydrate
• problem - empirical formula of a hydrocarbon
• problem - empirical formula of a C,H,O compound

Lesson 4 - Chemical Equations

• How to write and balance them
• Net ionic equations

Lesson 5 - Mass relations in chemical reactions

• A simple synthesis: C + 2H2 -> CH4
• Oxidation of waste: CH2O + O2 -> CO2 + H2O
• Production of H2SO4 from sulfur
• Steam reforming of natural gas: CH4 + H2O -> CO + 3H2

Lesson 6 - Limiting reactant calculations

• Identifying the limiting reactant
• mole-mole example: CH4 + 2O2 -> CO2 + H2O
• mass-mass example: CaF2 + H2SO4 -> 2HF + CaSO4

Lesson 7 - Volume relations in gas-phase reactions

• Law of combining volumes
• Adjusting your carburetor

Lesson 8 - Molar solution stoichiometry

• solution molarity
• a titration problem (Cl- in water by Ag+ titration)