Reductive ozonolysis of alkenes will lead to formation of aldehyde or ketones, oxidative ozonolysis of alkenes will lead to formation of carboxylic acids or ketones.
So, alcohol is not formed by ozonolysis of alkenes.
C-OH bond length in Among methanol, phenol and p-ethoxyphenol, C-OH bond length is least in phenol due to resonance and maximum in methanol due to lack of resonance whereas it will have some intermediate value in p-ethoxyphenol. phenol < p-ethoxyphenol < methanol
Methyl vinyl ether under anhydrous condition at room temperature undergoes addition reaction .
Phenol, is known as Carbolic acid.
Diazonium salt are hydrolysed to phonols.
Benzal chloride on hydrolysis gives benzaldehyde
Williamson's Synthesis
The correct answer for identifying the phenolic group is Option B, the Phthalein dye test.
Option A: Tollen's test - This test is used to identify aldehydes.
Aldehydes are oxidized to carboxylic acids by the Tollen's reagent (ammoniacal silver nitrate), and this reaction results in a characteristic silver mirror or a black precipitate of silver metal, which is not relevant to phenolic compounds.
Option B: Phthalein dye test - The phenolic group can be identified using the phthalein dye test.
In this test, phenols react with phthalic anhydride in the presence of a dehydrating agent, typically concentrated sulfuric acid, to form phthalein dyes.
A common example of a phthalein dye that can be formed in this manner is phenolphthalein, which is synthesized using phenol and phthalic anhydride.
These dyes exhibit color changes in different pH environments, which is a characteristic helpful in identifying phenolic compounds.
Option C: Carbylamine test - The carbylamine test, also known as the isocyanide test, is specific to primary amines.
In this reaction, primary amines are heated with chloroform and an alkali base, typically potassium hydroxide, to produce a foul-smelling isocyanide or carbylamine.
Since phenolic compounds do not have an amine group, they will not give a positive carbylamine test.
Option D: Lucas test - The Lucas test is used to classify alcohols of low molecular weight based on their reactivity with Lucas reagent, a solution of zinc chloride in concentrated hydrochloric acid.
The test differentiates between primary, secondary, and tertiary alcohols.
Phenols, which have an -OH group bonded to an aromatic ring, do not react in the same way as aliphatic alcohols in the Lucas test, and therefore, this test is not used to identify phenolic groups.
Thus, the test that is specifically used to identify a phenolic group is the Phthalein dye test.
Phenol are weakly acidic. Phenol is more acidic than alcohol & H2O statement (I) is correct. (II) is incorrect.
To determine which of the given compounds will readily react with dilute
, we need to understand the chemical reactivity of these compounds towards bases like sodium hydroxide (
). Here's a brief overview of each compound's reactivity towards
: Option A:
(Benzyl Alcohol) The presence of a benzyl group (a phenyl group attached to a CH2 group) adjacent to the hydroxyl group can somewhat increase the acidity of the hydroxyl hydrogen.
However, benzyl alcohol is still not significantly acidic to react vigorously with a weak base like dilute
.
Nonetheless, under certain conditions, it might undergo reactions, but not as readily as an acidic hydrogen-containing compound would.
Option B:
(Ethanol) Ethanol is a simple alcohol with no acidic hydrogen atoms that would react with
. The hydroxyl group in ethanol is not sufficiently acidic to deprotonate in the presence of a base like
, making it unreactive in this context. Option C:
(Phenol) Phenol contains a hydroxyl group directly attached to an aromatic ring.
This structural feature significantly increases the acidity of the hydroxyl hydrogen compared to alcohols.
The reason behind this is the stabilization of the phenoxide ion (the conjugate base) through resonance within the aromatic ring.
As a result, phenol can react with a weak base like
to form sodium phenoxide and water.
Option D:
(tert-Butyl Alcohol) tert-Butyl alcohol, being a tertiary alcohol, does not have a hydrogen atom on the carbon bearing the hydroxyl group that is acidic enough to react with
.
Tertiary alcohols, in general, are resistant to deprotonation because of the steric hindrance around the hydroxyl group and the lack of an easily removable hydrogen atom connected to the carbon with the -OH group.
Given the choices, the correct answer is Option C:
(Phenol), as it will readily react with dilute
due to the increased acidity of its hydroxyl group caused by the resonance stability of the phenoxide ion formed in the reaction.
Alcohol and ether are isomer with each other.
So, with same molecular formula we can make ether as well as alcohol.
For ex, With molecular formula C2H6O (1)
alcohol will be CH3CH2 OH (2)
ether will be CH3 O CH3 In Alcohol there is hydrogen bond and in Ether there is Van der walls force of attraction.
We know that H bond is stronger bond than van der walls force of attraction as the atoms of alcohol are strongly attached with each other by hydrogen bonding so tendency of vaporization of alcohol is less compared to ether.
In alcohol inter-molecular hydrogen bonding look like this -
Phenol on reaction with conc.
gives a mixture of
- and
- products (i.e.,
group, occupies
-,
- position). At room temperature
-product is more stable, which on treatment with conc.
will yield
-nitrophenol.
