Does the smell of alcohols increase as molar mass increases?

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The discussion centers on the relationship between the molar mass of alcohols and their odor intensity. It is noted that as the molar mass of alcohols increases, their vapor pressure decreases due to stronger intermolecular attractions. This suggests that higher molar mass alcohols may not necessarily smell stronger. The perception of smell is influenced by how well the alcohol molecules fit into olfactory receptors, which varies among different alcohols. Participants share personal experiences, indicating that different alcohols have distinct odors; for instance, n-butanol and n-pentanol are described as having a sweet smell, while shorter-chain alcohols like methanol and ethanol are perceived as more solvent-like. Overall, the relationship between molar mass and odor is complex and influenced by molecular structure and receptor interactions.
maturk
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Hello, I was just thinking about the pungent smell of alcohols and if they increase as the molar mass of the alcohol increases. For example, if I were to have samples of methanol, ethanol, propan-1-ol, butan-1-ol, and pentan-1-ol all at room temperature, would the alcohol's with the highest molar mass smell more "strongly" than the ones with lower molar masses. Or would it be the other way around?
 
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maturk said:
Hello, I was just thinking about the pungent smell of alcohols and if they increase as the molar mass of the alcohol increases. For example, if I were to have samples of methanol, ethanol, propan-1-ol, butan-1-ol, and pentan-1-ol all at room temperature, would the alcohol's with the highest molar mass smell more "strongly" than the ones with lower molar masses. Or would it be the other way around?

You would be having multiple things going on at the same time. As MW goes up, the vapor pressure goes down (due to increased intermolecular attraction). The "smell" will have to do with how the alcohol fits into the receptors in your nose. I believe that the current thinking is that these are activated by how well the molecule fits into the receptor. This "fit" might be different in the different receptors for the different alcohols. Certainly, you will have more non-specific interactions as the molecules increase in size.

In my own experience, the different alcohols have very different smells. n-Butanol and n-Pentanol smell very "sweet" to me, while the shorter alcohols smell more solvent-ey (not sure what word describes the smell of methanol and ethanol.)
 
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