My teacher showed us these examples in class, he says he need to be able to know when something is soluble in something else but i have no idea how to know. anyone have any rules on how to know?

This is the examples he gave us:
is CsI soluble in H2O? yes
is CH3OH soluble in H2O? Yes
is CH3OH soluble in NH3? Yes
is NaCl soluble in H2O ? yes
is C6H12O6 soluble in C6H6 ? No
is C6H12O6 soluble in H2O? Yes
is C6H6 soluble in C6H12? No
is CH3OH soluble in C6H6? No

... Please help i have a test soon. he says there will be other examples on test and not the ones above...

2 answers

Generally, like dissolves like.
CsI is polar. H2O is polar. yes.
CH3OH has OH. H2O has OH. yes.
I think C6H6 (is that benzene?) will dissolve in C6H12 (is that hexene). Both are non-polar solvents.
i see, thanks for the help!