how can i know if a solution is aqueous or solid? i have a test tomorrow and don't know how to do this PLEASE HELP!!! i have this question on my homework...Will precipitation occur when the following solutions are mixed?

Question

1. Na2Co3 and AgNO3
2. NaNO3 and NiSO4
3. FeSO4 and Pb(NO3)2

Answer 1

1. Silver carbonate is not soluble.
2. Nickel nitrate and sodium sulfate will be both soluble, no reaction.
3. Lead sulfate is not soluble.

Answer 2

Here is a simplified list of solubility rules.
http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.html