how do you predict the smell of a molecule using only its molecular formula?

Question

for example, if you had C10H16O
how could you tell from that what the smell would be like?

Answer 1

just the molecular formula isn't enough, but it's actually possible to guess if you know the structure. the Wikipedia article http://en.wikipedia.org/wiki/Aroma_compound gives some interesting examples.

specifically, C10H16O is probably the structure of camphor, which is a ketone. Ketones generally give off a strong scent, sometimes sweet - in this case, camphor is a major ingredient in Vicks Vaporub...

Answer 2

There are a lot of different molecules with that formula, since these atoms can be arranged in lots of different ways.But even if you knew which molecule it was, you couldn't tell without trying.

No one knows how to predict the smell of a molecule from its formula. The shape probably has something to do with it, as well as the polarity of the bonds, as these will affect how the molecule fits into detectors in the nose.