How do I know how many molecules a solute will split into when it dissolves in a solvent? I'm in high school and I'm learning about freezing point depression and boiling point elevation. I've been given this chemistry problem: 

Acetic acid has a boiling point elevation constant of 2.93 and a normal boiling point of 118.1 Celsius. What would be the boiling point of a solution made by dissolving 100.0 grams of calcium carbonate (CaCO3) in 400.0 grams of acetic acid?

This requires me to use the equation for boiling point elevation, that is:
ΔTb = Kb · bsolute · i, or change in temperature = the ebullioscopic constant * the molality of the solution * the number of ions the solute splits into.

My question is how does one determine i for a given solute in a case like this? Thanks for any help you can give!
You need to know the type of reaction that is taking place and what types of bonds are being made and/or broken to determine how many ions the given molecule will split into.