Question 71

Water (H2O) is often called the 'universal solvent' because it can dissolve more substances than any other liquid. This remarkable property is primarily due to its dipolar nature.

A water molecule has an uneven distribution of electric charge. The oxygen atom is more electronegative and pulls electrons closer to itself, resulting in a slight negative charge on the oxygen side and slight positive charges on the hydrogen sides. This creates a dipole moment, making water a polar molecule.

This polarity allows water molecules to interact strongly with other polar molecules (like sugar) and ionic compounds (like salts). The positive ends of water molecules are attracted to negative ions, and the negative ends are attracted to positive ions, effectively pulling the compound apart and dissolving it. This process is known as hydration.

While water also has a high specific heat and is an oxide of hydrogen, these properties do not primarily explain its exceptional dissolving ability.