Also called combination reactions Occurs when two or more substances combine to form a new compound A + X AX Example: Mg (s) + O 2(g) MgO (s) Reactions with oxides: Oxides of active metals will react with water to produce metal hydroxides.

Occurs when a single compound undergoes a reaction that produces two or more simpler substances. A compound breaks apart into simpler substances AX A + X

Decomposition of a Binary Compound - a compound made from two different elements is separated into its elements Example: 2H 2 O (l) electricity 2H 2(g) + O 2(g) The decomposition of a substance using an electric current is called electrolysis.

Decomposition of Metal Carbonates - Breaks down to form a metal oxide and carbon dioxide gas - Example: CaCO 3(s) CaO (s) + CO 2(g) Decomposition of Metal Hydroxides - Breaks down to form a metal oxide and water - Example: Ca(OH) 2(s) CaO (s) + H 2 O (g) Decomposition of Metal Chlorates - Breaks down to form a metal chloride and oxygen! - Example: 2KClO 3(s) 2KCl (s) + 3O 2(g) Decomposition of Acids - Break down to form nonmetal oxides and water - Example: H 2 CO 3(aq) CO 2(g) + H 2 O (l) - Example: H 2 SO 4(aq) SO 3(g) + H 2 O (l)

Also known as a single-replacement reaction Occur when an element is switched with an ion in a reaction. (The element may or may not take a similar charge as the ion it replaces!) A + BX AX + B or Y + BX BY + X Example: 2Al (s) + 3Pb(NO 3 ) 2(aq) 3Pb (s) + 2Al(NO 3 ) 3

Also called double-replacement reactions Occurs when two similarly charged ions are switched during a chemical reaction Only visible when a precipitate/gas/water is formed AX + BY AY + BX Example: 2KI (aq) + Pb(NO 3 ) 2 PbI 2(s) + 2KNO 3(aq)

Occurs when a substance combines with oxygen and releases large amounts of energy in the form of heat and light (explosion) Combustion of Hydrogen H 2(g) + O 2(g) → H 2 O (g) Combustion of a Hydrocarbon Example: C 3 H 8(g) + 5O 2(g) → 3CO 2(g) + 4H 2 O (g)