Final answer:
Water is referred to as the universal solvent because of its ability to dissolve a wide range of substances, attributed to its polar molecular structure that enables the formation of hydration shells around dissolved ions and polar molecules.
Step-by-step explanation:
Water is sometimes called the universal solvent because it has the ability to dissolve many different substances. This is due to water's molecular structure, which is polar, having slight positive and negative charges. These charges allow water to form hydrogen bonds with other charged and polar molecules, leading to the formation of hydration shells around dissolved ions and molecules. The polarity of water molecules enables them to interact with and dissolve ionic compounds like sodium chloride (table salt) as well as polar covalent compounds, making them 'water-loving' or hydrophilic. This exceptional solvency supports various biochemical reactions in living organisms, making water essential for life.