1. Major Types of Reactions
The 4 5
Major Types of Reactions

2. Synthesis Decomposition Single Displacement Double Displacement
We can classify any reaction in the universe as 1 of 5 types based on the reactants and the products. We can use a general equation (using X,Y or Z to represent any element) to show what will happen overall. These 5 types are :
Synthesis
Decomposition
Single Displacement
Double Displacement
Complete Combustion

3. Synthesis Reactions
idea : 2 or more reactants come together to make 1 product
general equation : X Y  XY
examples :
2H2 (g) + O2 (g)  2H2O(l) + thermal energy
thermal energy + N2 (g) + O2 (g)  2NO (g)
note: that a synthesis reaction may be endothermic or exothermic

4. Decomposition Reactions
idea : 1 compound will break down into 2 or more simpler compounds or elements
(this is the reverse of a synthesis reaction)
general equation : XY  X + Y
examples : H2CO3(aq) CO2 (g) + H2O(l)
carbonic acid carbon dioxide water
NH4NO3(s)  2H2O(l)+ N2O(g)

5. Single Displacement Reactions
idea : an element can be reacted with a compound and it will trade
places with one of its 2 parts
general equation : X + YZ  Y XZ
examples :
Mg (s) HCl (aq)  MgCl2 (s) H2 (g)
F2 (g) + 2 HCl (aq)  ???
2Ag(NO3) (aq) + Cu (s) Cu(NO3)2 (aq) + 2Ag (s)
2Na (s) H-OH (l)  2Na(OH) (aq) + H2 (g)

6. Double Displacement Reactions
idea : 2 compounds are reacted together and the first part of each compound will switch places
general equation : WX YZ  WZ YX
examples :
NaOH (aq)+ HCl (aq)  NaCl (aq) + H-OH (l)
Ba(OH)2 (aq)+Na2(SO4) (aq)  Ba(SO4) (aq) + 2 NaOH (aq)

7. Complete Combustion
Idea: the addition of a hydrocarbon to oxygen in the presence of a spark or flame will generate liquid water and carbon dioxide gas
General equation:
CxHy +?O2 (g)? CO2 (g) + y/2 H2O (l)
Example: C3H8 (g) + 5 O2 (g)  3 CO2 (g) + 4 H2O (l)

8. Practice p p p