Water can dissolve more substances than any other liquid because
- (a) it is dipolar in nature ✓ UPSC's answer
- (b) it is a good conductor of heat
- (c) it has high value of specific heat
- (d) it is an oxide of hydrogen
Why the answer is (a)
• Water is called the 'universal solvent' because its molecule is polar (dipolar): oxygen carries a partial negative charge and the hydrogens a partial positive charge — option (a).
• These charged ends surround and pull apart ions (as in NaCl) and form hydrogen bonds with polar molecules like sugar and alcohol, dissolving them.
• Heat conductivity (b) and specific heat (c) are thermal properties unrelated to solvent power; being an oxide of hydrogen (d) describes composition, not the reason for dissolving ability.
• Non-polar substances like oil do not dissolve in water for the same reason.
• Hence option (a).
Why the other options are wrong
- (b) it is a good conductor of heat
- Heat conduction has nothing to do with dissolving power.
- (c) it has high value of specific heat
- High specific heat is a thermal property, not a solvent property.
- (d) it is an oxide of hydrogen
- Chemical composition alone does not explain solvent ability.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2021, held on 10 October 2021. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.