Question

how can you tell a compound is more polar than another?

Answer 1

find the magnitude of the separation of partial charges (dipole moment)
read this: https://www.chem.queensu.ca/people/faculty/mombourquette/FirstYrChem/Molecular/dipole/

Answer 2

we can look at the compound's solubility in solvents.
the idea behind this is:

polar compounds are sooluble in polar solvents and non-polar compounds in non-polar or less polar solvents,

i guess this point is clear!!
u might even use dipole moment measurents tooo

Answer 3

i think you would run into problems if you used that method, say if you had 2 compounds with very low or very high solubilities.

Answer 4

By measuring dipole moment of compound we can tell their polarity