Question

Methanol and ethanol are miscible with water due to their:
A. covalent character
B. hydrogen bonding character
C. oxygen bonding character
D. nonpolar nature

Answer 1

The miscible nature of the polar molecule takes place because the formation of interaction is responsible for the generation of the mixture. The miscible character occurs if the molecules can easily diffuse with each other because of the chemical nature. This improves the chances of forming bonded structure so that the two components of the mixture are not separated.

Complete answer: Methanol and ethanol are miscible with water even though these organic molecules are the organic solvents. This condition is because of the specific functional group that is part of both the molecules when it mixes with water. It is already known that water can be an intermolecular hydrogen bond as there are $H$ residues and $O$ residues which are part of the structure of water $\left( {{H_2}O} \right)$. The formation of hydrogen bonds occurs between $H$ and a specific electronegative element like $F$, $N$ and $O$. Here the two organic molecules are methanol and ethanol which have the specific functional group known as an alcoholic group $\left( { - OH} \right)$. The presence of this alcoholic group is responsible for the formation of hydrogen bonded structure with water. The $O$ residues present in the water and alcoholic compounds can form the hydrogen bond with the $H$ residues. This together forms the intermolecular hydrogen bonding structure. The polar covalent bond $O - H$ in these alcoholic groups is responsible for the formation of the interaction. This helps the polar molecule mix with water forming a miscible mixture of the alcoholic chemicals with the water. This hydrogen bonding character helps in the bonded structure which can properly help in mixing of the molecules in the given solution.

Hence the correct option is (B).

Note: The importance of interactions can be present when one of the molecules mixes with another and for the stability of the molecules. The molecules involved need to have the chemical nature that facilitates the interaction.