What is a Chemical Reaction A chemical reaction

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

Equation Type of Reaction Definition Synthesis Two or more elements or compounds combine to make a more complex substance Decomposition Compounds break down into simpler substances Single Replacement Occurs when one element replaces another one in a compound AB + C → AC + B Double Replacement Occurs when different atoms in two different compounds trade places AB + CD → AD + CB A + B → AB AB → A + B 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 O 2 as a reactant • ALWAYS has CO 2 and as H 2 O • products. Ex: Combustion of napthalene: C 10 H 8 + 12 O 2 ---> 10 CO 2 + 4 H 2 O