Quantities in Chemical Reactions

Recipes demonstrate numerical relationships between ingredients in cooking.
Chemical equations serve as recipes for chemical reactions, showing reactant-product relationships.

Mole-to-Mole Conversions: Ratios from balanced equations can be expressed in moles.
Mass-to-Mass Conversions: Relationships between masses of reactants and products derived from chemical equations.
Key Concepts:
- Limiting reactant: The reactant that gets consumed first.
- Theoretical yield: Maximum amount of product from limiting reactant.
- Actual yield: Amount produced in practice; usually < theoretical yield.
- Percent yield: $(\text{Percent Yield} = \frac{\text{Actual Yield}}{\text{Theoretical Yield}} \times 100\%)$

Identify limiting reactant based on given amounts.
For reactions, perform calculations to find theoretical yield, then compare to actual yield to calculate percent yield.

Enthalpy (H): Measure of heat absorbed/emitted during reactions at constant pressure.
- Positive H: Endothermic (absorbs heat).
- Negative H: Exothermic (releases heat).
Stoichiometric amounts determine heat exchange, linked with balanced chemical equations.

Amount of heat emitted/absorbed is dependent on quantities of reactants.
Heat relationships can be constructed based on stoichiometric ratios in balanced equations for calculating total heat emitted during reactions.