Why this chapter matters
Reaction accounting is the foundation for predicting product amounts and evaluating whether claims are chemically consistent.
What you will learn
- Balance molecular and net ionic equations while conserving atoms and charge.
- Use stoichiometric ratios to identify limiting reactants and theoretical yield.
- Classify common reaction patterns, including precipitation, acid-base, and redox processes.
Lessons in this chapter
- Balancing and representing reactionsTranslate word descriptions to balanced chemical equations in correct physical states.
- Net ionic equationsSeparate spectators from reacting species in aqueous systems.
- Limiting reactant and yieldUse mole ratios to find which reactant controls product amount.
- Redox bookkeepingTrack oxidation states to identify oxidation and reduction in reactions.
Study task
Balance four mixed reaction equations and solve one full stoichiometry chain from reactant masses to percent yield.
Chapter checkpoint
For 2H2 + O2 -> 2H2O, if 5.0 mol H2 reacts with 2.0 mol O2, which reactant is limiting?
The reaction needs 2 mol H2 per 1 mol O2. For 2.0 mol O2, 4.0 mol H2 is required. Since 5.0 mol H2 is available, O2 is limiting.