34
votes
Accepted
Is alcohol really a solution?
Technically, alcohol is the name of a class of organic compounds containing one or several hydroxyl groups.
Colloquially, the term "alcohol" is understood as you have described: A solution (of ...
- 10.8k
28
votes
Accepted
What chemical properties of ethanol make it usable for drinks as compared to that of methanol?
The problem arises from the metabolized products of methanol. Methanol oxidizes in the liver by an enzyme called alcohol dehydrogenase to formaldehyde which is further metabolized to formic acid by ...
- 24.9k
22
votes
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Un-denaturing industrial alcohol
(I'm no chemist, but here's my take on it)
Let's see: I’m an alcoholic, and I really hate having to dole out large amounts of cash to purchase your usual "drinking"-ethanol.
So I get this amazing ...
- 18.5k
21
votes
When I burn isopropyl alcohol (IPA), it burns orange. But when I burn ethyl alcohol, it burns totally blue. Why is this?
IPA has a different carbon:hydrogen ratio than ethanol. There is more incomplete combustion occurring with IPA, hence the smoky orange flame and smell of soot. Ethanol combusts more completely, ...
- 487
19
votes
Accepted
Ring contraction in pinacol rearrangement of cyclohexane-1,2-diol
Background
You don't specify whether we are starting with cis- or trans-cyclohexane-1,2-diol, but it doesn't matter since both isomers will interconvert under the reaction conditions. Therefore we ...
- 84k
18
votes
Accepted
Reactions of alcohol with sulfuric acid
This article on Wikipedia says your compound, ethyl sulphate, can be synthesized, by adding sulfuric acid drop-wise to boiling ethanol and temperature should be kept below 413K which agrees with your ...
- 4,585
18
votes
Accepted
Why do hydroxyl groups only produce a singlet in proton NMR?
You are both right and wrong.
At low temperatures, the NMR spectrum will indeed be as you predicted: the $\ce{H}$ from $\ce{OH}$ will produce a quartet and likewise the $\ce{H}$ from $\ce{CH_3}$ will ...
- 1,222
18
votes
Why is thionyl chloride preferred for preparing alkyl chlorides from alcohols?
Preparation of alkyl chlorides from alcohols by thionyl chloride is preferred over other methods mentioned because of the following reasons :
$$\ce{R-OH + PCl5 → R-Cl + POCl3 + HCl ↑}$$
$$\ce{...
- 1,429
18
votes
Accepted
When I burn isopropyl alcohol (IPA), it burns orange. But when I burn ethyl alcohol, it burns totally blue. Why is this?
Interesting observation. The blue flame color of all hydrocarbon fuels is due to the emission small diatomic carbon species such $C_2$ or CH. There is nothing magical about IPA having a yellow flame. ...
- 38.6k
17
votes
Accepted
Why is thionyl chloride preferred for preparing alkyl chlorides from alcohols?
Thionyl chloride is preferred for preparing alkyl chlorides from alcohols because the by-products formed in the reaction are $\ce{SO2}$ and $\ce{HCl}$ which are in gaseous form and escape into the ...
- 1,254
17
votes
Accepted
Is it correct to say that ethenol is an alcohol?
The golden book states that ethenol is an alcohol:
Enols
Alkenols; the term refers specifically to vinylic alcohols, which have the structure $\ce{HOCR'=CR2}$.
However, the modifier "vinylic"...
- 6,851
17
votes
Accepted
What happens if you carbonate ethanol?
Carbon dioxide is in fact roughly ten times as soluble in ethanol as in water [1](https://doi.org/10.1016/j.fluid.2006.04.017) (meaning you need more dissolved under pressure to get that bubbling ...
- 51.4k
16
votes
Accepted
What is the name origin of ester?
The term "Essigäther" is actually the German name for ethyl acetate i.e Essig = "vinegar" + Äther = "ether". "vinegar" becomes acetic, hence ethyl acetate ...
- 24.9k
14
votes
Accepted
Are there ethanol and methanol analogues with more than one hydroxyl group?
Generally speaking, they're called diols when bearing two hydroxyl groups. If they're on the same C, this is called a geminal diol, if they are on neighboring Cs, they're called vicinal diols. The C ...
- 341
13
votes
Benzene from cyclopropane-1,2,3-triyltrimethanol in acidic medium
I have not written the steps for carbocation formation, simple dehydration.
- 5,446
12
votes
Accepted
How to explain this acid-catalysed acetal rearrangement mechanistically?
You have managed to draw the correct acyclic hydrolized compound with a decent mechanism.
This is a problem that can be solved by numbering the carbon atoms. Number the carbon atoms sequentially ...
- 42.5k
12
votes
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Formation of toluene from (cyclobutane-1,2,3-triyl)trimethanol using conc. sulphuric acid
Seeing the reaction given here, I assume that is an on-paper reaction that takes place and that all three alcoholic groups are dehydrated.
The mechanism (on paper) seems to be as follows
Dehydration $...
- 6,840
11
votes
Why does alcohol crack acrylic (plexiglass)?
If a solvent causes an amorphous polymer to craze, this is because the polymer is principally soluble in it. It diffuses into the surface, but without instantly dissolving it, as the polymer chains ...
- 11.9k
11
votes
Is alcohol really a solution?
Tschoppi’s answer is technically correct, since it is nigh impossible to create a pure compound without any contaminants. The highest-grade liquids I can remember seeing on SigmaAldrich’s web pages ...
- 67k
11
votes
Is sodium borohydride really a better base than an alcohol?
General considerations
It’s not the basicity that is the important factor here, it is the nucleophilicity. The hydride ion, whether present as tetrahydridoborate or as a lone hydride is a very lousy ...
- 67k
11
votes
Un-denaturing industrial alcohol
The reason criminals don't undenture alcohol is probably because it's cheap and easy to make your own alcohol at home. Plus it's legal in the US (click on G1) and most other English-speaking ...
- 111
11
votes
Un-denaturing industrial alcohol
In Soviet Russia, where alcoholism was widespread and homebrewing illegal, undenaturing alcohol was a pretty common thing - a part of national culture, in a way - along with such practices as:
...
- 30.9k
11
votes
Accepted
Why can't alcohols form hydrogen-bonded dimers like carboxylic acids?
The strength of a hydrogen bond somewhat depends on the $\ce{X-H\bond{...}X}$ angle that the hydrogen-bonding hydrogen forms with the two electronegative elements $\ce{X}$. In our case, carboxylic ...
- 67k
11
votes
Accepted
Why do Grignard reagents add to propargyl alcohols?
The addition of Grignards to propargyl alcohols occurs via the alkoxide salt, after deprotonation:[1]
Here:
the reactivity may be explained by the stabilising influence of complexation;
the ...
- 70.8k
11
votes
Why don’t Grignard reagants react with their alcohol products?
The addition of a Grignard to a carbonyl doesn't form an alcohol—not directly at least. It forms an alkoxide ion (i.e. the conjugate base of an alcohol).
Only when that reaction is complete, is water (...
- 70.8k
10
votes
Accepted
Producing ketones from secondary alcohols using hydrogen peroxide
I think it is possible to use hydrogen peroxide. This paper discusses it: http://greenchem.uoregon.edu/PDFs/ResourceID88.pdf
Other alternatives:
Pyridinium Chlorochromate (or PCC for short)
Dess-...
- 8,425
10
votes
Accepted
Is methanol really more acidic than water?
First, water’s $\mathrm{p}K_\mathrm{a}$ in water is $14$ as explained here. This means that $\ce{H2O}$ is slightly dissociated in liquid form, such that $[\ce{H+}] = [\ce{HO-}] = 10^{-7}$.
Second, I ...
- 772
10
votes
How to convert ethanol to benzoic acid?
Here is how I would do it.
Part I: Blue
First, ethanol 1 is oxidised to acetaldehyde 2, which undergoes nucleophilic addition with $\ce{KCN}$ and $\ce{HCN}$ to form the hydroxynitrile 3, and finally ...
- 586
10
votes
Does benzene react with steam to create an alcohol?
Strange as it may seem, benzene can be reacted with steam over a suitable catalyst [1]. The result is a complete breakdown to simpler molecules like methane and carbon dioxide. Typical conditions ...
- 51.4k
10
votes
Accepted
Is Pinacol rearrangement the source for the ring expansion?
Your first and third structures are good but the arrow pushing in the second structure doesn't get the job done. As you have noted, diol 1 forms carbocation 2a the more stable of the two options. Now ...
- 16k
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