60
votes
Accepted
What's the biggest organic molecule that could have a smell?
I'll quote from $\ce{[1]}$:
The general requirements for an odorant are that it should be
volatile, hydrophobic and have a molecular weight less than
approximately 300 daltons. Ohloff (1994) has ...
- 12.3k
52
votes
Accepted
Why does burnt hair smell bad?
Hair is largely (~90%) composed of a protein called keratin, which originates in the hair follicle.
Now, keratin is composed of a variety of amino acids, including the sulfur containing amino acid, ...
- 18.8k
52
votes
Accepted
What causes the "rotting fish smell"?
The "fishy" odor that you're familiar with is brought about by a whole bunch of compounds, and not any single one. Then again, if we were to narrow this down a bit, we could say that simple nitrogen ...
- 18.8k
49
votes
Accepted
Why does lemon juice reduce the "fish" odor of sea food — specifically fish?
There are two cases, both related to acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice.
Fish, especially sea fish, naturally contain trimethylamine-N-oxide $\...
- 43.3k
25
votes
Accepted
The smell of wet gypsum
It's from weathering (chemical, microbial, other) of gypsum ($\ce{CaSO4\cdot 2H2O}$) and mostly arises from the evolution of $\ce{H2S}$.
That said, there are numerous other sulfur-containing compounds ...
- 10.9k
21
votes
Accepted
Does a smell imply particles or chemicals in the air?
Smell works because your nose detects substances in the air.
Everything you can smell is the result of a molecule carried by air interacting with complex proteins in the nose/mouth (smell and taste ...
- 37.2k
19
votes
Do almonds smell like they do because of cyanide?
Almonds smell like they do mostly due to the presence of benzaldehyde:
This colorless liquid has a characteristic almond-like odor. Benzaldehyde is the primary component of bitter almond oil and ...
- 10.9k
14
votes
How to I neutralize the smell of (VERY) spoiled milk
The disgusting smell is probably butyric acid. Try adding a base: For example, washing soda (sodium carbonate), or perhaps drain cleaner (sodium hydroxide, be careful with this one, this is very ...
- 157
11
votes
Accepted
Is sodium chloride really odourless? If yes, what do I smell?
Your table salt is not just $\ce{NaCl}$; there are countless other compounds which make up the table salt.
Here are a few:
$\ce{NaCl}$ - the main component
Iodine in the form of $\ce{I-}$ and $\ce{...
- 2,116
10
votes
What causes the smell of something being "musty"?
The "musty smell" is from mold, sometimes bacteria. Different compounds are responsible depending on the species. Some examples: trichloroanisole, tribromoanisole, dimethylmethoxypyrazine. Search "...
- 1,362
10
votes
How does the smell of a compound come about, and is it possible to define a smell?
Smell is what you feel when molecules of some compound (and not any kind of radiation, mind you) touch the olfactory nerves deep inside your nose. It is just another property of a compound, like ...
- 31.4k
10
votes
Smell produced in reaction of sodium hydroxide and aluminium
Oscar Lanzi's answer addressed the points correctly. This reaction of Al + NaOH pellets is used in drain openers for obvious reasons. The reaction is so exothermic that solution can start boiling. It ...
- 42.3k
8
votes
How do people know HCN smells like almonds?
how do people know HCN smells like almonds
Bit late to the party, but I'm missing a crucial part in the existing answers. So here are my 2ct: HCN does not smell like [bitter] almonds.
Personally, I ...
- 3,264
8
votes
Accepted
How does the smell of a compound come about, and is it possible to define a smell?
As a sensation, olfaction does not seem to possess the same status as, say, vision. Most biologists, indeed most people not directly involved with fragrances or flavours seem to think that odour ...
- 5,164
7
votes
Do almonds smell like they do because of cyanide?
As someone who has smelled a lot of HCN during experiments I can tell you that the smell of HCN is nothing like the smell of Benzaldehyde or any almond oils you can buy as flavors. I never really ...
- 4,342
7
votes
I left scented candles in a polypropylene container. How do I remove the smell?
The answer depends on (1) how patient you are (how much time you have), (2) how low a concentration of the offending substances you need to obtain, (3) whether you have someplace you can leave the box ...
- 22.7k
6
votes
How does the smell of a compound come about, and is it possible to define a smell?
The molecular mechanism of smell is still unknown. What can be said is that molecules of all sorts are usually identified in proteins (probably of many different types) and that the effect this ...
- 31k
6
votes
Accepted
Why is O2 (Oxygen) colorless and odorless while O3 (Ozone) is a pale blue gas with a distinctively pungent smell?
The real answer for why ozone smells the way it does has little to do with chemistry but perhaps a lot to do with evolution.
The specific reason why it is coloured far more intensely than oxygen is ...
- 37.2k
6
votes
Why is O2 (Oxygen) colorless and odorless while O3 (Ozone) is a pale blue gas with a distinctively pungent smell?
Our perception of colour and smell involve different chemistry so there is no reason why they should be related. For example, what ever the chemistry of smell is (and its not certain what this is) it ...
- 31k
6
votes
Smell produced in reaction of sodium hydroxide and aluminium
The consensus is that the odor could come from multiple causes:
Droplets of solution: Evolved gas (or even gas being blown over the liquid, as with winds blowing over a lake or ocean) can carry tiny ...
- 61.1k
5
votes
Accepted
Why is pencil lead smelly?
None of the carbon allotropes have a smell. If you smell something from a pencil lead (graphite), then it will be from the impurities in it.
Graphite is made from impure organic compounds that ...
- 254
5
votes
What is responsible for the odor of gasoline?
Many of the components of gasoline (petrol) have notable odours
A simple starting point for understanding the odour of gasoline is the typical composition of the product. That composition varies a ...
- 37.2k
5
votes
What's the biggest organic molecule that could have a smell?
(on behalf of the old-school chemists)
Iodoform (393.732 g/mole) has a strong characteristic odour.
5
votes
Accepted
Why does tert-butyl alcohol smell like camphor?
They are more similar than you think if you view them using space filling models
Part of the problem in judging how things smell is that smell is a very complex sense. There are possibly hundreds of ...
- 37.2k
4
votes
Accepted
What chemical is responsible for the distinictive odor of Scotch tape?
This is a long answer, but according to this:
While some pressure sensitive tapes are still prepared with natural
rubber, the majority are now made using mostly synthetic materials.
The ...
- 17.6k
4
votes
What is the "smell" of solid sulfur
The primary candidates for volatilization of odorous sulfur gases are $\ce{SO2}$ and $\ce{H2S}$. Unless the elemental sulfur has been physically ground and dispersed into the air it is not likely the ...
- 17.6k
4
votes
What is the chemistry behind smell of human perspiration(sweat)?
In addition to simpler lower carboxylic acids contributing rather to socks smell (see Q: Why do socks stink?), some notable representatives contributing to the human axilliary (armpit) odor are
...
- 6,272
4
votes
How to remove formaldehyde (smell) from clothes/jeans?
Formaldehyde is indeed used for disinfection, but usually there is a subsequent procedure involving formaldehyde neutralization with $10\%$ to $25\%$ aqueous ammonia solution introduced (as a spray) ...
- 38.4k
4
votes
Accepted
Is there any relation between resonance and smell of a hydrocarbon?
I wish I could convey the spirit of Professor Louis Fieser on the development of organic chemistry. I couldn't find it in his textbooks, but in class, it went something like this:
Coal distillation ...
- 14.2k
4
votes
What compounds smell like burning rubber or tar?
Check local history:
Was the land used as a dump or filled in with waste wood? Creosote is derived from tar, and it is used as a wood preservative. If creosoted wood, such as railroad-ties, was used ...
- 34.8k
Only top scored, non community-wiki answers of a minimum length are eligible