Correct Option (A):
Water is a highly polar molecule due to the significant difference in electronegativity between oxygen and hydrogen atoms. The oxygen atom carries a partial negative charge, while the hydrogen atoms carry partial positive charges. This dipolar nature allows water molecules to form strong electrostatic interactions (hydrogen bonds) with other polar molecules and to effectively solvate ions from ionic compounds. This ability to interact with a wide range of substances, both ionic and polar, is why water is often referred to as the "universal solvent" and can dissolve more substances than most other liquids.
Incorrect Options:
- Option 2: Water's ability to conduct heat (thermal conductivity) is a physical property related to energy transfer, not its capacity to dissolve substances. Pure water is a poor conductor of electricity and heat; its conductivity increases significantly only when dissolved ions are present.
- Option 3: High specific heat capacity refers to the amount of heat energy required to raise the temperature of a substance. While this is an important property of water, contributing to temperature regulation, it does not directly explain its solvent capabilities.
- Option 4: Water being an oxide of hydrogen (H₂O) describes its chemical composition. While chemically accurate, this fact alone does not explain the mechanism or extent of its solvent power, which is primarily attributed to its molecular polarity.