I have been wondering how something smells.
How come something smells the same as other thing? What is similar in them?
Like what is the chemistry behind a particular smell of a substance?

For example compounds with SH (thiol) smell awful and similar, so what is similar between them? I know SH, but I am asking why can't they smell different.


closed as too broad by andselisk, Todd Minehardt, ron, Nilay Ghosh, Jon Custer Aug 7 '17 at 13:27

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 2
    $\begingroup$ You aren't surprised that two things may have the same color, are you? $\endgroup$ – Ivan Neretin Aug 7 '17 at 11:56
  • 2
    $\begingroup$ I'm afraid unless you provide a certain example you question is way too broad. $\endgroup$ – andselisk Aug 7 '17 at 11:57
  • 3
    $\begingroup$ This is probably more of a biology question, no? Smell is a property of the interaction between a molecule and the receptors in the nose. Although compounds with a similar smell may have the same functional groups, they may be very different. On the other hand, there is D/L- limonene that has a different smell for each of the two isomers. $\endgroup$ – gilleain Aug 7 '17 at 12:38
  • 1
    $\begingroup$ The bit in your post that's suggestive of being off-topic(ish): "smell awful and similar". Smell is human perception, not a physical quantity, and hence doesn't really pertain to "pure" Chemistry. Sure, in Chemistry we talk about "smell" a lot, but that's really just limited to the laboratory ( "Phenolic" smell, "Pungent" smell, etc), but wanting to know how something has a particular odor is really more of a human physiology question. I'm not saying there's no Chem. involved...but this is way better off on the Biology.SE. As such, I vote to keep this closed. $\endgroup$ – paracetamol Aug 7 '17 at 15:55
  • 1
    $\begingroup$ Question could be migrated, but premise isn't true, I'm pretty sure one can make thiols with distinct smell. It's not that simple. $\endgroup$ – Mithoron Aug 7 '17 at 18:14