Write the balanced chemical equation for the following reaction. Also, classify the reaction as sythesis, decomposition, single replacement, double replacement, or combustion.
aluminum sulfate + barium chloride —> aluminum chloride + barium sulfate

Reaction: Al2(SO4)3 + 3BaCl2 --> 2AlCl3 + 3BaSO4

Type: Double Replacement

Explanation:

1.) First you need to understand what the different reactions are

a.) Synthesis: is a reaction where two or more substances will combine with each other to make one product.

          Ex:  A + B → AB

b.) Decomposition: when one compound breaks down into two or more substances. (Opposite of synthesis)

          Ex:  AB → A + B

c.) Single Replacement: when one element replaces another one in a reaction

          Ex:  A + BC → AC + B

d.) Double Replacement: when the positively charged cations and negatively charged anions of the reactants trade places. Normally this will be the two outer elements combining and the two inner ones combining.

          Ex: AB + CD →  AD + CB

e.) Combustion: when a substance reacts with oxygen gas and releases energy as light and heat.

         Ex: CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g)

2.) From there you can write out the formula of the different reactants and products and balance the equation.