Chemical Reactions

What is a Chemical Reaction? A chemical reaction is the process by which one or more substances are changed into one or more different substances.

Indications of a chemical reaction: Production of heat or light Production of a gas Formation of a precipitate A precipitate is a solid that forms when two or more liquids are combined. Unexpected Color Change

Types of Chemical Reactions: Synthesis Decomposition Single Replacement Double Replacement Combustion Oxidation and Reduction Neutralization of Acids and Bases

Type of Reaction Definition  Equation Synthesis Decomposition Single Replacement Double Replacement Two or more elements or compounds combine to make a more complex substance A + B → AB AB → A + B Compounds break down into simpler substances Occurs when one element replaces another one in a compound AB + C → AC + B Occurs when different atoms in two different compounds trade places AB + CD → AD + CB A = Red B = Blue C = Green D = Yellow

Combustion reactions Combustion –when oxygen combines with a hydrocarbon to form water and carbon dioxide. This will produce heat and light. ALWAYS includes O2 as a reactant ALWAYS has CO2 and as H2O products. Ex: Combustion of napthalene: C10H8 + 12 O2 ---> 10 CO2 + 4 H2O