Most Asked Questions
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Alcohols, Phenols And Ethers

- Get to know usually which areas are frequently asked in the JEE mains and Advanced examinations.
1
JEE Mains

Reaction of alchols or phenols with grignard reagent

When an alcohol is treated with a Grignard reagent , the H atom of the -OH group combines with the alkyl part of the Grignard reagent to give an alcohol.
g of an alcohol, was added to and the gas evolved measured mL at STP. The molecular mass of will be?
A
B
C
D
When phenyl magnesium bromide reacts with tertiary butanol, which of the following is formed? 
A
Tertiary butyl methyl ether
B
Benzene
C
Tertiary butyl benzene
D
Phenol

Why phenols being stronger acids than alcohols

The alcohols are less acidic then phenols because it is very tough to remove the H ion from alcohol. Phenol can lose hydrogen ion easily because phenoxide ion formed is stabilized to some extent as negative charge on the oxygen atom is delocalised around the ring. De-localized charge means negative charge is distributed almost equally through the compounds. The more stable ion is, the more likely it is to form.

I. Ethanol
II. Acetic acid
III. Phenol
IV. Acetonitrile
The acidity of compounds I-IV in water follows the order:
A
B
C
D

Dehydration by protonic acids

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Alcohols, when treated with protonic acid, produce alkenes.
Rate of dehydration of the following in increasing order is:
A
B
C
D
none of these

The major product of the given reaction is:
A
B
C
D
2
JEE Advanced

Reimer-Tiemann reaction

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When phenol is treated with chloroform in the presence of aqueous sodium hydroxide at 340 K followed by hydrolysis, an aldehyde group is introduced into the ring mainly at o-position.
Identify the correct option(s) related with the physical properties of the unknown compounds [X] and [Y] formed as major and minor product respectively in the given reaction.
This question has multiple correct options
A
Water solubility of [Y] is greater than [X]
B
Boiling point of [Y] is greater than [X]
C
Melting point of [Y] is greater than [X]
D
[X] is more volatile than [Y]

Reaction of phenol and ferric chloride

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Phenol with ferric chloride forms a complex which give violet colouration, hence this reaction is used for identification of phenol.
Two aromatic compounds having formula which are easily identifiable by solution test (violet colouration) are:
A
o-cresol and benzyl alcohol
B
m-cresol and p-cresol
C
o-cresol and p-cresol
D
methyl phenyl ether and benzyl alcohol

Williamson synthesis

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content Text
The product is:
A
B
C
D