What type of reaction is al + 3cuso4 --> al2(so4)3 + 3 cu

It's a Single Replacement (or Displacement) Reaction because the equation follows the basic format for that type of reaction.

For Single Replacement Reactions, the general formula is:

AB + C = AC + B

So, if there's an element and compound on both sides of the equation, it's single replacement.

the dependant variable is spilled water

the independent is the heat