5: Introduction to Chemical Reactions

5.1: The Law of Conservation of Matter 物质守恒定律

5.2: Chemical Equations 化学方程式

Chemical reactions are represented by chemical equations that list reactants and products. Proper chemical equations are balanced; the same number of each element’s atoms appears on each side of the equation.

5.3: Quantitative Relationships Based on Chemical Equations 基于化学方程式的定量关系

The coefficients in a balanced chemical equation give the ratios in which molecules of substances react and are produced in a chemical reaction.

5.4: Some Types of Chemical Reactions

Combination (composition) Reactions 化合反应

Decomposition Reactions 分解反应

Combustion Reactions

5.5: Oxidation-Reduction (Redox) Reactions 氧化还原反应

Chemical reactions in which electrons are transferred are called oxidation-reduction, or redox, reactions. Oxidation is the loss of electrons. Reduction is the gain of electrons. Oxidation and reduction always occur together, even though they can be written as separate chemical equations.

5.6: Redox Reactions in Organic Chemistry and Biochemistry

Redox reactions are common in organic and biological chemistry, including the combustion of organic chemicals, respiration, and photosynthesis.