Study Notes on Chemical Reactions

Section 9.1 Reactions and Equations

• Chemical Change: Process involving substances transforming into new ones.

• Key Terms:

  • Reactant: Starting substance in a reaction.

  • Product: Substance formed in a reaction.

  • Chemical Equation: Notation that represents the relative amounts of reactants and products in a reaction.

• Balancing Equations: Chemical equations must be balanced to reflect the conservation of mass; coefficients indicate the number of molecules or moles.

Section 9.2 Classifying Chemical Reactions

• Types of Reactions:

  • Synthesis: Two or more reactants forming one product.

  • Combustion: Reaction with oxygen releasing energy.

  • Decomposition: A compound breaks down into simpler products.

  • Single Replacement: One element replaces another in a compound.

  • Double Replacement: Exchange of ions between two compounds.

Section 9.3 Reactions in Aqueous Solutions

• Aqueous Solution: Mixture where water is the solvent.

• Ionic and Net Ionic Equations:

  • Complete Ionic Equations show all particles, while Net Ionic Equations include only species that participate in the reaction.

• Reactions in Aqueous Solutions: Typically involve double-replacement reactions that can produce precipitates, water, or gases.