1. Reactions
By Mr. M

2. Reactions
Interactions between atoms that create a compound not originally present
A reaction is indicated by an arrow
Ý means reaction goes both directions
← means reaction goes to the left in the equation
↓ means reaction goes to the right in the equation
Next to an element/compound you may see certain symbols
(g) means gas
(l) means liquid
(s) means solid
(ppt) means precipitate or an item that appears
(aq) means aqueous or dissolved in water

3. Parts of an equation The equation for a reaction has 2 parts
The reactants are what get used up
The products are what are formed
Reactants ↓ products
You can speed up a reaction by adding a catalyst
You can slow down a reaction by adding an inhibitor

4. Types There are several types of reactions (abbreviated rxns)
For right now you are only responsible for five types of reactions
Combustion
Synthesis
Decomposition
Single displacement
Double displacement

5. Combustion Combustion is also known as burning
Carbon compound + O2 ↓ CO2 + H2O
It can also be carbon compound +O2 ↓ CO + H2O but this is called incomplete combustion

6. Synthesis Multiple items make one item only
Also called combination or addition or composition
General Equation
A + B  AB
Mg + O2 ↓ MgO skeletal equation
2Mg + O2 ↓ 2MgO balanced chemical equation

7. Decomposition You start with only one item, but it becomes many
General
AB ↓ A + B
H2O2 ↓ H2O + O skeletal
2H2O2 ↓ 2H2O + O balanced

8. General: AB + C  AC + B  + + Single Displacement Zn Cl Cu Cl Zn Cu
Also called single replaced
Cations switch places or anions switch  Zn Cl Cu + Cl Zn Cu +
General: AB + C  AC + B

9. Activity Series
Elements can switch places if something more reactive is added, but no reaction occurs if something less reactive is added
The activity series gives the order of what can switch
K can replace anything in the list
Au can be replaced by anything

10. General: AB + CD  AD + CB  + + Double Displacement O Mg Ca O Mg Ca
Also called single replacement or metathesis
Both cations and anions switch S O  Mg Ca + O S Mg Ca +
General: AB + CD  AD + CB