Salt, or sodium chloride, and water differ physically in that salt is an ionic compound dissolving into ions when in water, whereas water is a polar molecule dissolving many but not all substances due to its ability to form hydrogen bonds.
Salt (sodium chloride) and water have very different physical properties due to the nature of their chemical structures and the types of bonds they form. Sodium chloride is a compound with a uniform and definite composition, consisting of equal parts of sodium (Na+) and chloride (Cl-), forming ionic bonds. When dissolved in water, the salt dissociates into these ions but retains its chemical identity.
Water, on the other hand, is a polar molecule capable of forming hydrogen bonds. It can dissolve many substances, like salts, sugars, and acids, turning them into electrolytes. However, water repels nonpolar molecules such as oils due to its polar nature. This polarity makes water an excellent solvent for ionic and polar substances but not for nonpolar substances like fats, lipids, and oils.
While salt solutions can vary in composition, water and salt are both pure substances with distinct and consistent properties. This difference in properties is essential for methods used to separate mixtures. For example, physical methods can separate a mixture of salt and water, while a compound such as salt requires a chemical process to decompose it into its elemental constituents.
The probable question may be:
Salt and water have very different physical properties, explain.