Chemical Reactions 1.A chemical change is any change in which a new substance is formed. Evidence: Release of energy as heat and light, change in color, formation of gas, change in odor, etc.

Common Types of Chemical Reactions single displacement: A + BC  AC + B double displacement: AB + CD  AD + CB synthesis (formation): A + B  AB decomposition: AB  A + B combustion: C x H y + O 2  CO 2 + H 2 O

Types: Single displacement Example: Zn + CuCl 2  Zn Cl Cu + General: AB + C  AC + B Cl Zn Cu + Metal replaces a metal

Types: Single displacement Example: KBr + Cl 2  Cl K Br + General: AB + C  AC + B + Cl K Br Nonmetal replaces a nonmetal

Types: Double displacement Example: MgO + CaS General:AB + CD  AD + CB S O  Mg Ca + O S Mg Ca +

Types: Double displacement Sub categories: General:AB + CD  AD + CB Precipitation Reactions AB (aq) + CD (aq)  AD (aq) + CB (s) Acid / Base Reactions HB + COH  H 2 O + CB

Types: Synthesis (Combination) Example C + O 2 OO C +  OO C General: A + B  AB

Types: Decomposition Example: NaCl General: AB  A + B  Cl Na Cl + Na

Types: Decomposition Example 2HgO  O Hg O OO + General: AB  A + B

Types: Combustion C x H y + O 2  CO 2 + H 2 O A hydrocarbon (could also have oxygen) burning “completely” Completely meaning it forms carbon dioxide and water

Decomposition

Double Displacement

Synthesis (Combination)

Single Displacement

Combustion CO 2 + H 2 O O2O2

Combustion CO 2 + H 2 OO2O2

Common Types of Chemical Reactions single displacement: A + BC  AC + B double displacement: AB + CD  AD + CB (examples: precipitation and acid/base) synthesis (combination): A + B  AB decomposition: AB  A + B combustion: C x H y + O 2  CO 2 + H 2 O