Types of Reactions Continued

Last day we learned about 3 types of reactions: Synthesis, Decomposition and Single Replacement.
Today we learned the next 3 types of reactions: Double Replacement, Neutralization and Combustion

First let's look at double replacement reactions.
The general formula of double replacement reactions goes as follow:
AB + CD ---> AD + CB
Simply put it means that the metals or the non-metals trade places.
Eg. CaCl2 + Al2O3 ---> CaO + AlCl3


Of course this then has to be balanced
 Eg. 3CaCl2 + Al2O3 ---> 3CaO + 2AlCl3


However we need to be able to determine if a reactions is actually going to occur. To do so we must look at the "Table of Solubilities"

Using the table find the anion (negative ion) on the let and see if it is soluble or or not soluble. If it is not soluble the compound is a solid. If it is soluble the compound is aqueous.

Now what does this have to do with determining if a reaction is going to occur?
If at least one of the products has a change of state ie. aqueous to solid a reaction occurs
If no change of state happens no reaction happens.

Once you know a reaction is going to occur you need to make a net ionic equation. You only do this with reactions that actually occur!!!
You take reactants that make up the solid and use them on the left hand side of the equation (write their charges and numbers as well) and write the numbers of the solid product on the right hand side.

Eg. 4PO4  -3  (aq) + 3Ti +4 (aq) ---> Ti3(PO4)4


Combustion
Is a reaction where burning of air is involved.
General Formula:  AB + O2 ---> AO + BO
Eg. CH4 + 4O2 ---> CO2 + 2H2O


Neutralization
Is a reaction where and acid and alkali combine to form a salt and water
General Formula: HA + BOH ---> H2O + BA

Eg. 2HCl + Ca(OH)2 ---> H2O + CaCl2





A neutralization reaction is just a special double replacement reaction, therefore you need to make a net ionic equation as well.