[anishd]

For instance, would -OR be more polar than C=0; if so, why?

Do double bonds enhance or have no effect on solubility and/or boiling point?

Do double bonds enhance the acidity?
For this question, I understand that you can look at the conjugate and cand etermine if it's more stabilized or not, but I'm specifically referring to double bonds.

Also, as a bonus question, on the caffeine molecule. Why is the sp3 Nitrogen the least basic? If it's sp3, doesn't that mean that it's more likely to donate its electrons, rather than contribute to resonance?

Thank you so much,
Anish