8.1 Writing and Balancing Chemical Equations
Chemical equations are symbolic representations of chemical and physical changes. Formulas for the substances undergoing the change (reactants) and substances generated by the change (products) are separated by an arrow and preceded by integer coefficients indicating their relative numbers. Balanced equations are those whose coefficients result in equal numbers of atoms for each element in the reactants and products.
8.2 Classifying Composition, Decomposition and Combustion Reactions
Three types of chemical reactions were learned: a composition reaction, a decomposition reaction and a combustion reaction. A composition reaction produces a single substance from multiple reactants. A decomposition reaction produces multiple products from a single reactant. Combustion reactions are the combination of some compound with oxygen to make oxides of the other elements as products (although nitrogen atoms react to make N2).
8.3 Classifying and Completing Single and Double Displacement Reactions
Two types of chemical reactions were learned: single displacement and double displacement. A single displacement reaction replaces one element for another in a compound. The periodic table or an activity series can help predict whether single displacement reactions occur. A double displacement reaction exchanges the cations (or the anions) of two ionic compounds. A precipitation reaction is a double displacement reaction in which one product is a solid precipitate.
Attribution & References
Except where otherwise noted this page is adapted by Adrienne Richards from:
- 8.1 – “Summary 4.1. Writing and Balancing Chemical Equations” in Chemistry 2e (OpenStax) by Paul Flowers, Klaus Theopold, Richard Langley, & William R. Robinson, licensed under CC BY 4.0. Access for free at Chemistry 2e (OpenStax).
- 8.2 and 8.3 – “Chapter 4: Chemical Reactions and Equations: Composition, Decomposition, and Combustion Reactions”and “Chapter 4: Types of Chemical Reactions: Single and Double Displacement Reactions” In Introductory Chemistry: 1st Canadian Edition by David W. Ball and Jessica A. Key, licensed under CC BY-NC-SA 4.0.