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प्रश्न
Ortho and para nitrophenols are more acidic than phenol. Draw the resonance structures of the corresponding phenoxide ions.
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उत्तर
Resonance structures of o-nitrophenoxide ion
Resonance structures of p-nitrophenoxide ion
Resonance structures of phenoxide ion
In substituted phenols, electron-withdrawing groups such as the nitro group increase the acidic strength of phenol. This effect becomes more potent when such groups are present at the ortho and para positions. This is because of the effective delocalisation of the anion of the phenoxide ion. Hence, o- and p-nitrophenols are more acidic than phenol.
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संबंधित प्रश्न
Give reasons for the following:
o-nitrophenol is more acidic than o-methoxyphenol.
Write the mechanism of the following reaction:
Write the mechanism of the following reaction :
Give the equation of the following reaction:
Dilute HNO3 with phenol.
Name the reagent used in the following reaction:
Oxidation of a primary alcohol to carboxylic acid.
When 3-methylbutan-2-ol is treated with HBr, the following reaction takes place:
\[\begin{array}{cc}
\phantom{...................................}\ce{Br}\\
\phantom{..................................}|\\
\ce{CH3 - CH - CH - CH3 ->[HBr] CH3 - C - CH2 - CH3}\\
|\phantom{.........}|\phantom{...................................}|\phantom{...........}\\
\ce{CH3}\phantom{...}\ce{OH}\phantom{...............................}\ce{CH3}\phantom{.......}\\
\end{array}\]
Give a mechanism for this reaction.
(Hint: The secondary carbocation formed in step II rearranges to a more
stable tertiary carbocation by a hydride ion shift from 3rd carbon atom.)
Which of the following are used to convert RCHO into RCH2OH?
(i) H2/Pd
(ii) LiAlH4
(iii) NaBH4
(iv) Reaction with RMgX followed by hydrolysis
Lucas test is done to differentiate between ____________.
Primary and secondary alcohols on the action of reduced copper give:
During dehydration of alcohols to alkenes by heating with cone. H2SO4 the initial step is ____________.
\[\ce{CH3CH2OH}\] can be converted into \[\ce{CH3CHO}\] by ______.
Mark the correct increasing order of reactivity of the following compounds with HBr/HCl.
| (a) |  |
| (b) |  |
| (c) |  |
Suggest a reagent for the following conversion.
Alcohols react with active metals e.g. Na, K etc. to give corresponding alkoxides. Write down the decreasing order of reactivity of sodium metal towards primary, secondary and tertiary alcohols.
What is Lucas reagent?
What happens when (CH3)3 C – OH is heated with Cu/573 K?
Write the chemical equation in support of your answer.
Which of the following alcohols will not undergo oxidation?
Write the mechanism of acid-catalysed dehydration of ethanol to yield ethene
