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

Phenols are more acidic than alcohols because the phenoxide ion formed after losing a hydrogen ion (H⁺) is stabilized by resonance. The negative charge on the oxygen atom is delocalized over the aromatic ring, which makes the phenoxide ion more stable. On the other hand, the alkoxide ion formed from alcohols does not have such resonance stabilization, making alcohols less acidic.

When benzyl phenyl ether is heated with HI, it undergoes cleavage to form phenol and benzyl iodide. The reaction proceeds as follows: C₆H₅CH₂O-C₆H₅ + HI → C₆H₅OH + C₆H₅CH₂I. Therefore, the products obtained are phenol (option 1) and benzyl iodide (option 3).

The C-O-C bond angle is influenced by steric hindrance around the oxygen atom. In the case of $ (CH_3)_2 CH - O - CH (CH_3)_2 $, the two bulky isopropyl groups will create more steric repulsion, causing the bond angle to increase to minimize this repulsion. Therefore, the C-O-C bond angle will be maximum in $ (CH_3)_2 CH - O - CH (CH_3)_2 $.

The reaction between sodium ethoxide and bromocyclopropane does not yield an ether. This is because bromocyclopropane undergoes a nucleophilic substitution reaction where the strain in the three-membered ring leads to the formation of a ring-opened product rather than an ether.

$ H_2O $ containing hydrogen bond,

$ SO_2 + 2H_2S \rightarrow 3S + 2H_2O $

The boiling point of hydrides generally increases as we move down the group in the periodic table due to an increase in molecular weight. However, $H_2O$ has an exceptionally high boiling point due to hydrogen bonding. Among $H_2S$, $H_2Se$, and $H_2Te$, $H_2S$ has the lowest molecular weight, and hence, the lowest boiling point.