Types

There are two main types of reactions which are chemical and nuclear. For now we shall deal only with chemical reactions. A chemical reaction is

There are six main categories of chemical reactions

1. Synthesis - the combination of one or more atoms or
2. Decompostion - the seperation of a molucule
3. Single Replacement - the replacement of one atom or molucule with another
4. Double Replacement - the exchange of an atom or molucule with another
5. Combustion - the breakdown of a molucule through the use of oxygen

It is of course possible that any one equation could fall under more than one category.

Predicting

There is a basic procedure when trying to predict the product of a certain set of reactants:

First look for the precence of ions. If one or more is present, you are probably dealing with some type of synthesis or replacement. If it begins with two ions bonded together and one is free, most of the time it will be a single replacement reaction. If it begins with two and two, look for the strong possiblity of double replacement. If it is one and one, it is either synthesis or no reaction at all. In all of these cases the most important part is to make sure you keep negatives with positives and keep track of charges: if one atom has 2+ for its charge, it's going to need two 1- atoms to keep the balance.

Combustion and decompisition are closely related; bith result in something less complex than that which was present in the reactants. Combution, though, must have oxygen present in the reacts and it usually has water and energy as two of its products.

Examples

It is very important to be able to determine types of reactions. It will aid you when you are trying to predict outcomes and analysing results. It is important to note that some reactions will be able to fit into multiple categories, so there are some gray areas. Here are a few examples of each reaction type (note: ">>" means "yields"):

Synthesis:

Single Replacement:

Double Replacement:

Decomposition:

Combustion: