# Tag Info

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### 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 ...
• 10.6k
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### 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 ...
• 22.8k

### Migratory aptitude in pinacol-pinacolone rearrangement

In the pinacol rearrangement, a 1,2-diol is treated with acid and rearranges to a carbonyl compound. Here is a reaction scheme showing a mechanism for the rearrangement. In this case the molecule is ...
• 82.6k
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### Why is pyridine used when making tosyl esters from alcohols?

The function of pyridine is actually not so simple and not so easy to notice at first glance. There is a fundamental reason why pyridine is used to promote the acylation reaction, which is that it can ...
• 910

### 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, ...
• 477
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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 ...
• 18.1k
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### 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 ...
• 1,182
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### 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 ...
• 82.6k
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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?

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. ...
• 33.7k
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### 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 ...
• 4,415

### 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{...
• 1,379
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### 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"...
• 6,758
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### 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 ...
• 1,316

### Testing isopropyl alcohol purity

If the isopropanol mixture was bought commercially, the chances that it contains significant amounts of methanol or ethanol are fairly small, I think. (I've never seen commercial isopropanol in the ...
• 20.4k
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### Reaction of alcohols with PCl5 and PCl3

Remember your general chemistry. In an acid-base reaction, the equilibrium favors the side of the reaction with the weaker acid/base pair. Strong bases have weak conjugate acids. Strong acids have ...
• 41.8k
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### 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 ...
• 22.8k
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### Why can't alcohols turn blue litmus red?

Litmus is a weak acid, with a $\mathrm{p}K_\mathrm{a}$ of about 6.5. Alcohols are extremely weak acids, with $\mathrm{p}K_\mathrm{a}$'s (typically) around 17. The litmus itself is a much stronger ...
• 5,487
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### 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 ...
• 331
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### 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 ...
• 41.8k

### Benzene from cyclopropane-1,2,3-triyltrimethanol in acidic medium

I have not written the steps for carbocation formation, simple dehydration.
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• 82.6k

### 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 ...
• 11.6k

### Strength of hydrogen bonding in phenol or methanol

Let me answer the second question first, because the answer is so much easier: Of course the hydrogen bond strength depends among others upon the carbon oxygen is attached to. Consider phenol and ...
• 64.8k
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### 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 ...
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