There are only five (5) different types of chemical reactions: 1) Double Replacement 2) Single Replacement 3) Synthesis 4) Decomposition 5) Combustion

Occur between two ionic compounds Does not happen with covalent compounds

Involves an exchange of cations The cation of one compound trades

places with the cation of another compound to form two new compounds

occur in solution when the compounds are in an aqueous state (aq) reactants are either aqueous to begin with, or

solid compounds dissolved in water to form an aqueous solution of ions

in order to drive the reaction, one of the products must be removed from the aqueous solution

this can occur via one of three ways:

1) Formation of a precipitate (an insoluble solid forms in the solution)

i.e.:

AgNO3 (aq) + NaCl (aq) = NaNO3 (aq) + AgCl (s)

Solid silver chloride is formed as precipitate and comes out of the solution

2) Formation of a gas i.e.:

FeS (aq) + 2 HCl (aq) = H2S (g) + FeCl2 (aq) Hydrogen sulfide gas is formed and

comes out of the solution

3) Water is formed when a hydrogen cation unites with a hydroxide anion

i.e.:

NaOH (aq) + HCl (aq) = HOH (l) + NaCl (aq) Water (HOH) is formed and comes out of

the solution

Double replacement reactions always have two ionic compounds on the REACTANTS side

*Two compounds react to form two new compounds* AB + CD CB + AD

A & C are cations, B & D are anions A & C switch places

Atom (s) of a lone element replace the atom (s) of an element in a compound Metals replace metals (or cations replace

cations) Non-metals replace non-metals (or anions

replace anions)

Metal Cation Replacement: For the reaction:

A + BC B + AC

A and B are cations A “replaces” B in the compound

Non-metal Anion Replacement:For the reaction:

D + EF ED + F

D & F are anionsD “replaces” F in the compoundNon metal replacements usually involve

halogens

Thermite Thermite is a reaction that creates molten iron

from rust and aluminum powder. This reaction is typically used in certain types

of welding (or for just melting stuff)

Fe2O3 + 2 Al → 2 Fe + Al2O3

Activity Series: A characteristic of metals and halogens

referring to their reactivity Determines whether or not a single

replacement reaction will occur or not Metals: on the handout provided there is an

activity series of metals arranged in order of decreasing activity

Non-metals (Halogens) : as you move down the group on the periodic table activity decreases

A single replacement reaction WILL NOT OCCUR if the reactivity of the pure element reactant is less than that of the compound reactant i.e.:

Sn (s) + NaNO3 (aq)

no reaction b/c tin is less reactive than sodium

A single replacement reaction WILL OCCUR if the reactivity of the pure element reactant is greater than that of the compound reactant i.e.:

Zn (s) + H2SO4 (aq) ZnSO4 (aq) + H2 (g)

Reaction occurs because the reactivity of zinc is higher than hydrogen

Single replacement reactions ALWAYS have 1 lone element and 1 compound on the reactants side and the products side

Reactants will always be: 1 lone element + 1 compound

Products will always be: 1 lone element + 1 compound

Occurs when a single compound breaks down into two or more components

Energy is required for them to occur Reactants will always be:

1 compound Products will always be:

ALWAYS more products than reactants 2 components (either compounds or

elements) i.e.:

AB A + B

One unit breaks down into its component parts

i.e. – Remember N’Sync? They split up leaving the resulting in Justin Timberlake and four guys we don’t remember.

2 H2O2 (aq) → 2 H2O (l) + O2 (g)

Hydrogen peroxide naturally decomposes into water and oxygen gasIf you have old hydrogen peroxide in your house, it may have turned into a bottle of water

Don’t try and drink it though. Obviously.

Occurs when two or more components come together to form one compound

Energy is released when these reactions occur

Reactants will always be:ALWAYS more reactants than products!2 or more components (either elements or

compounds) Products will always be:

1 single compound i.e.:

A + B AB

Two individual components coming together to form one unit

i.e. – Beyonce & Jay-Z were both awesome on their own, but joined together to become one, even better entity.

Decomposition and Synthesis Reactions are opposite processes

Special Case #1: A non metal oxide + water combine to form

an acid i.e.: SO3 + H2O H2SO4

AND an acid will decompose to form a non-metal oxide + water i.e.: H2SO4 SO3 + H2O

Special Case #2 A metal oxide + water combine to form a

metal hydroxide i.e.: CaO + H2O Ca(OH)2

A metal hydroxide will decompose into a metal oxide + water i.e.: Ca(OH)2 CaO + H2O

Special Case #3: All carbonates decompose into carbon dioxide

and an oxide i.e.: CaCO3 CaO + CO2

Vice versa for synthesis/formation reactions Special Case #4:

All chlorates decompose into oxygen and a binary salt

i.e.: KClO3 KCl + O2

Vice versa for synthesis/formation reactions

Also known as burning or explosions Hydrocarbon

Compound composed of only carbon and hydrogen and sometimes oxygen

Reactants will always be:Hydrocarbon + oxygen

Products will always be:Carbon dioxide + water

i.e.:C6H6 + O2 CO2 + H2O