Questions tagged [alcohols]
For questions about saturated and unsaturated alcohols, their physical properties, their reactions, etc. For questions about phenol, use the [phenols] tag instead.
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Differences between phenols and alcohols
I know phenols are more acidic as compared to alcohols, but are they considered different from alcohols?
Sure, you can study something as a subset, but are phenols considered a subset of alcohols, or ...
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Is alcohol really a solution?
A friend recently sent me the following chemistry joke:
As a lover of puns, I'd like to enjoy it, but I think that it is actually false the way it is phrased.
A solution is defined as: "a ...
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Reaction of alcohols with PCl5 and PCl3
The reaction of alcohols $\ce{ ROH }$ with $\ce{ PCl5 }$ and $\ce{ PCl3 }$ yields an alkyl halide $\ce{RCl}.$ With $\ce{ PCl5 }$, the reaction is quite simple leading to the formation of $\ce{ RCl }$ ...
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Migratory aptitude in pinacol-pinacolone rearrangement
I am confused about the migratory aptitude of various groups, as there are many different orders for the same given in different places, especially about -Ph and -H. I would like to know if someone ...
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Strength of hydrogen bonding in phenol or methanol
I wanted to know whether hydrogen bonding is stronger in phenol or methanol.
I saw on Wikipedia about the enthalpies of hydrogen bonding in various cases.
but could not find the answer to this ...
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Un-denaturing industrial alcohol
I have a question regarding the denaturation of industrial ethanol with methanol to discourage its consumption.
The boiling point of methanol is 64.7 °C, while the boiling point of ethanol is 78.37 °...
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Why is pyridine used when making tosyl esters from alcohols?
Tosyl chloride is used to make a hydroxyl group into a better leaving group. However, when the reaction of tosyl chloride and an alcohol occurs, a weak base such as pyridine should be used. Why?
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Is there a point at which Ethanol (E10) fuel becomes harmful to gas tanks or engines if not used?
This is not the typical chemistry question on this website, but I think it's an important practical question.
When I got a gas string trimmer, the woman who worked at the gardening shop told me that ...
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Reactions of alcohol with sulfuric acid
I knew two chemical reactions of alcohol with sulfuric acid
$\ce{CH3CH2OH + H2SO4 -> CH2CH2}$
Here product is having a double bond (ethene) and this reaction happens at 443 K temperature.
$\ce{...
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Can we synthesize alcohols by the photolysis of hydrogen peroxide?
As I was going through my revision of organic chemistry, I came across free radical substitution of alkanes with halogens. In a similar process where we use hydrogen peroxide, instead of chlorine, so ...
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Why does hand sanitizer turn into a liquid after coming out of the bottle?
Hand sanitizer is a gel in its bottle, but when I pour it on my palm, it turns into a free flowing liquid. Why does that happen?
It doesn't turn to a liquid when I pour it on my floor or my table. ...
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When I burn isopropyl alcohol (IPA), it burns orange. But when I burn ethyl alcohol, it burns totally blue. Why is this?
I burned them in a small aluminium tray. While IPA is burning orange, it produced the smell of soot, but while ethanol is burning blue there isn't any smell.
Also, ethanol made the tray really cold ...
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Why does alcohol crack acrylic (plexiglass)?
I have seen videos and discussions about alcohol cracking acrylic, and waterblock manufacturers reminding users to not use alcohol in cooling systems with plexiglass acrylic, but why is this so?
The ...
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What happens if you carbonate ethanol?
The electronics youtuber bigclivedotcom has an on-and-off-again series where he carbonates various types of alcohol and comments on the taste. One thing he's noticed is that the stronger the alcohol, ...
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How do you create primary amines from alcohols?
By a primary amine I mean a compound where the hydroxyl group of the corresponding alcohol is replaced with an amine group.
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Is it correct to say that ethenol is an alcohol?
IUPAC Gold Book defines alcohols as:
Compounds in which a hydroxy group, $\ce{–OH}$, is attached to a
saturated carbon atom $\ce{R3COH}$.
However, Wikipedia says that:
Vinyl alcohol, also ...
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Why can't alcohols form hydrogen-bonded dimers like carboxylic acids?
Carboxylic acids such as acetic acid are capable of forming dimers:
I'm wondering why alcohols like ethanol don't generally form dimers. In the diagram below, the oxygen atom on the left ethanol ...
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What are the practical differences between the various DMSO oxidations (Swern, etc.)?
Recently, I was reading a paper about a total synthesis of (+)-rubriflordilactone A (the article is open access: Angew. Chem. Int. Ed. 2015, 54 (43), 12618–12621). In two different steps where an ...
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Why do hydroxyl groups only produce a singlet in proton NMR?
Take, for example, methanol ($\ce{CH3OH}$). The hydroxyl proton ($\ce{-O$\color{red}{\ce{H}}$}$) is three bonds away from three more protons ($\ce{-C$\color{blue}{\ce{H}}$_3}$), which aren't ...
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Ring contraction in pinacol rearrangement of cyclohexane-1,2-diol
I came across this question in three different textbooks.
The question was: What is the major product obtained on dehydration (treatment with concentrated $\ce{H2SO4}$) of cyclohexane-1,2-diol.
I ...
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Most stable conformational isomer of 3-methoxycyclohexan-1-ol
Among the following, the most stable isomer is?
I am aware of the fact that equatorial substituents are more stable than axial substituents but couldn't proceed to apply it here. However the answer ...
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Synthetic route for the conversion of ethanol to but-1-yne
How do I convert $\ce{CH3CH2OH}$ (ethanol) to $\ce{CH3CH2C#CH}$ (but-1-yne) ?
I'm not too good with reaction mechanisms and conversions are beyond me.
My Attempt:
I've searched through a couple of ...
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How do I predict the solubility of a compound in a mixture of water and an organic co-solvent?
I'm trying to predict the solubility of long alcohols (e.g. 1-octanol, 1-decanol or 1-dodecanol) in a mixture of water and an organic co-solvent such as DMSO, acetonitrile or ethyl acetate.
For ...
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Do azeotropic mixtures evaporate proportionally?
Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point?
Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an ...
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Reaction of secondary alcohol with ammoniacal silver nitrate (Tollens' reagent)
What are the products of the reaction of 2-butanol with silver nitrate?
For the moment, I am a bit stumped as I only have $\ce{AgNO3}$ as an oxidizing agent to form a carboxylic acid from an aldehyde....
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What is the name origin of ester?
Ester is quite a random nomenclature for a compound derived from a parent acid and parent alcohol.
Is there any reasoning behind using the word 'ester' to name such compound (for memorising purpose)?
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Would it be possible to create a (non-toxic) alcoholic drink that, when zapped with laser, changes color?
Would it be possible to create a (non-toxic) alcoholic drink that, when zapped with a 0.5mW laser pointer, changes color?
This would be mainly for the visual effects (bartender show) so it should not ...
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Why do Grignard reagents add to propargyl alcohols?
In Phil Baran's lectures on heterocyclic chemistry at Scripps, one of the lecture problems is concerned with this synthesis of Vioxx:
The first step supposedly involves an anti addition of the aryl ...
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Why does a proton prefer to attack a double bond instead of protonating an alcohol in a reaction of unsaturated alcohol with sulphuric acid?
A solved problem in Organic Chemistry by Solomons, Fryhle and Snyder asked to write the mechanism for the following transformation in the presence of sulphuric acid ($\ce{H2SO4}$):
The mechanism ...
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Why do tosylation and mesylation of alcohols follow different mechanisms?
Why do the tosylation and mesylation of an alcohol proceed via different mechanisms?
More specifically,
In tosylation, the lone pair of the alcohol attacks the sulfur in TsCl, but why does it not ...
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Why is the melting point of tert-butyl alcohol 140 °C higher than that of sec-butyl alcohol?
This is one of the most drastic differences in a physical property I've ever seen for two such similar molecules, and in a simplistic sense anyway the difference lies in the opposite direction from ...
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Is sodium borohydride really a better base than an alcohol?
I have learnt that sodium borohydride can reduce aldehydes, ketones and acyl chlorides into alcohols. However, it fails to react with esters or acid anhydrides.
On the other hand, alcohols — ...
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Can a six member ring expand to achieve octet completion to stabilize a carbocation?
(Probably unnecessary background: I came up with this carbocation while predicting the major product of $\ce{NaNO2/HCl}$ with 1-(methylamine)cyclohexan-1-ol)
Will the following carbocation ...
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Testing isopropyl alcohol purity
I'm curious how to test purity of isopropyl alcohol? I simply got very curious today. I bought rubbing alcohol and it doesn't say what's the purity anywhere. It could be 70%, but it could also be 90%, ...
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Is methanol really more acidic than water?
The question Why is methanol more acidic than water? deals with the reasoning of why methanol is more acidic than water. However, as mentioned in the comments of that question, the acidity constant of ...
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Why is SN2 favored greatly over SN2' in this reaction?
Secondary allylic halides can be produced in high yield with the following Mitsunobu-type reaction:[1]
The yield being $94~\%$.
The last step in the mechanism is:
Why is the $\mathrm{S_N2}$ reaction ...
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Is there a way to turn alcohol into a solid gel?
I'm wondering if there is a way to turn alcohol or another bacteria killing substance into a solid gel form, sort of like the gel you can use to clean a keyboard.
Source: Aliexpress.com Computer ...
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Conversion of an alcohol to a methyl group
I'm only interested in the first conversion: D to E.
I've been thinking about this for a little bit. My first thought was to use $\ce{TsCl}$ to make a good leaving group then a $\ce{Me}$ nucleophile. ...
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Which electronic effects are responsible for the reduction of nucleophilicity of a hydroxy group orthogonal to an ester?
I am facing a similar synthetic problem as Boekman Jr. et al noted in their synthesis of Tetronolide.[1] I will quote their’s rather than disclosing my actual synthetic problem, but note that the key ...
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Why is thionyl chloride preferred for preparing alkyl chlorides from alcohols?
Why is thionyl chloride ($\ce{SOCl2}$) preferred for preparing alkyl chlorides from alcohols, as opposed to say $\ce{PCl5}$ or $\ce{PCl3}$ ?
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Have "molecular clusters" for azeotropes been identified?
A different question about azeotropes got me thinking about this point again. Azeotropes have a very specific composition so it seems that the azeotrope ought to have some sort of physical structure. ...
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Identification of types of alcohols
An unknown compound was found to react with sodium hydride with the evolution of hydrogen. The compound could not be acetylated under the normal conditions for acetylation. The compound resisted ...
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Polarity of alcohols and their miscibility in water
I am an AP Chemistry student and there is a small detail concerning polarity of molecules that I am confused about.
My review book (Princeton review) says that ethanol has stronger intermolecular ...
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How could alcohol be made into a powder?
In the news recently is 'Palcohol', powdered alcohol, that you add to water or existing liquids to make it alcohol. Presumably this would dissolve and break apart into alcohol and {some other compound}...
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What is the reason that tertiary alcohol pKa is higher than primary alcohol pKa?
A tertiary alcohol has a $\mathrm{p}K_\mathrm{a}$ of 18 while a primary alcohol has a $\mathrm{p}K_\mathrm{a}$ of 16.
Shouldn't the tertiary alcohol be more acidic since its conjugate base is more ...
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Why does LiAlH4 reduce the double bond of cinnamaldehyde, whereas it does not reduce the double bond in crotonaldehyde?
$\ce{LiAlH4}$ is a strong reducing agent capable of breaking the double bonds. It does break the double bonds in cinnamaldehyde.
Shouldn't $\ce{LiAlH4}$ be able to break the double bond in ...
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Why is an alcohol proton so shielded?
Considering how electronegative oxygen is, why is the chemical shift of alcohol protons (1H-NMR) not so high? The chemical shifts of the protons on 3-propanol are about 1.20 for the carbon-1 hydrogens,...
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Why can't I dry/concentrate ethanol using calcium chloride ... or can I?
My (very unreliable) school textbook tells me:
Lower alcohols form a solid derivative with certain metal salts.
and,
It is for this reason that ethanol cannot be dried/concentrated using ...
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Why does formaldehyde exist primarily as the gem-diol in aqueous solution?
From Wikipedia,
Methanediol is the product of the hydration of formaldehyde $\ce{H2C=O}$, and predominates in water solution: the equilibrium constant being about $10^3$ and in a 5% by weight ...
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How to explain this acid-catalysed acetal rearrangement mechanistically?
I have spotted a protecting acetal group and thought this would undergo hydrolysis … My working is such:
But I cannot get to the desired isomer. Could someone please help? (Diagrams would be very ...
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