Alcohols of low molecular weight are:
Correct answer: A. Soluble in water
- A. Soluble in water
- B. Insoluble in water
- C. Soluble in water on heating
- D. Insoluble in all solvents
Explanation
Alcohols of low molecular weight are soluble in water. This is because the alcohols can form hydrogen bonds with water molecules. Hydrogen bonds are attractions between a hydrogen atom that is bonded to a highly electronegative atom, such as oxygen, and a lone pair of electrons on another atom. The hydroxyl group in an alcohol contains an oxygen atom that is bonded to a hydrogen atom. This oxygen atom is highly electronegative, so it can form hydrogen bonds with water molecules. The water molecules can then form hydrogen bonds with each other, which results in the alcohol being soluble in water. As the molecular weight of the alcohol increases, the solubility in water decreases. This is because the hydrocarbon chain on the alcohol becomes more hydrophobic, which means that it does not like to interact with water. The hydrophobic part of the alcohol prevents it from forming hydrogen bonds with water molecules, which reduces its solubility in water.
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About Alcohols and Phenols
Alcohols are classified as primary, secondary or tertiary and studied through their hydrogen bonding, acidity, oxidation and reactions with active metals, acids and halogenating agents. Phenols require separate treatment because the hydroxyl group is attached to an aromatic ring, making their acidity and electrophilic substitution different from ordinary alcohols.
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