Alcohol, phenol & ether MCQs for NEET — Chemistry Questions with Answers

The NCERT states, 'The –OH group in alcohols and phenols is involved in intermolecular hydrogen bonding... It is interesting to note that boiling points of alcohols and phenols are higher in comparison to other classes of compounds, namely hydrocarbons, ethers and haloalkanes of comparable molecular masses.' Intermolecular hydrogen bonding requires more energy to overcome, leading to higher boiling points.

As per the NCERT text, 'Benzylic alcohols: In these alcohols, the —OH group is attached to a $sp^3$—hybridised carbon atom next to an aromatic ring.'

The NCERT defines vinylic alcohols as compounds where the –OH group is bonded to a carbon-carbon double bond, i.e., to a vinylic carbon or to an aryl carbon. The example given is $CH_2 = CH – OH$.

According to Table 7.2 in the NCERT, the common name for $CH_3OCH_3$ is Dimethyl ether.

The NCERT states, 'In fact, alcohols and phenols are Brönsted acids i.e., they can donate a proton to a stronger base (B:).'

The NCERT states, 'Ethers are classified as simple or symmetrical, if the alkyl or aryl groups attached to the oxygen atom are the same... Diethyl ether, $C_2H_5OC_2H_5$, is a symmetrical ether'.

The NCERT explains, 'The acidic character of alcohols is due to the polar nature of O–H bond. An electron-releasing group (–CH3, –C2H5) increases electron density on oxygen tending to decrease the polarity of O-H bond. This decreases the acid strength. For this reason, the acid strength of alcohols decreases in the following order: Primary > Secondary > Tertiary.'

According to the provided context, o-Cresol has the IUPAC name 2-Methylphenol. Ortho- (o-) indicates substituents at positions 1 and 2, and since phenol is the parent, the methyl group is at the 2-position.

Ethers are classified as simple or symmetrical if the alkyl or aryl groups attached to the oxygen atom are the same, and mixed or unsymmetrical if the two groups are different. In $\\text{C}_2\\text{H}_5\\text{OCH}_3$, the groups are ethyl and methyl, which are different, making it an unsymmetrical ether. $\\text{CH}_3\\text{OCH}_3$ and $\\text{C}_2\\text{H}_5\\text{OC}_2\\text{H}_5$ are symmetrical ethers. $\\text{C}_6\\text{H}_5\\text{OCH}_3$ is also an unsymmetrical ether, but the question asks 'which of the following', and $\\text{C}_2\\text{H}_5\\text{OCH}_3$ is explicitly mentioned as an example of an unsymmetrical ether in the text.

The context states that Benzene-1,3-diol is commonly known as Resorcinol.