Properties of Water

Water is a compound made up of two hydrogen atoms and one oxygen atom, denoted as H2O.
It is a polar molecule, with an uneven distribution of charge that leads to the negative end (oxygen) and the positive end (hydrogen).
Water’s polarity allows it to act as a universal solvent, dissolving a wide range of substances.

Water as a Universal Solvent

Due to its polarity, water can dissolve many ionic and covalent compounds, such as salts, sugar, and gases including oxygen and carbon dioxide.
The ability of water to dissolve substances makes it essential for life as it carries nutrients and waste materials in and out of cells.
However, not all substances dissolve in water. Substances that do not mix with water are termed hydrophobic or water-fearing, e.g., oils and fats.

Water boils at 100 degrees Celsius at standard pressure and freezes at 0 degrees Celsius.
The high boiling point of water relative to its molecular weight is due to hydrogen bonding. Water molecules form hydrogen bonds with each other which require more energy to break.

The density of water means that it is less dense as a solid than as a liquid, which is why ice floats on water.
Water can exist in three states – solid (ice), liquid (water), and gas (steam).

Water exhibits high surface tension due to the hydrogen bonding between its molecules. This means that water can ‘stick together’ and form droplets.
The high surface tension enables capillary action, a phenomenon that allows water to travel up narrow tubes against the force of gravity. This is essential for plant life as it helps transport water from the roots to the leaves.

Water has a high specific heat capacity, which means it can absorb a lot of heat before its temperature increases. This makes it ideal for cooling systems.
Its high latent heat of vaporisation means that it requires a lot of energy to change from a liquid to a gas. This is the principle behind sweating – as sweat evaporates from the skin, it cools the body down.

Due to its unique properties, water plays a critical role in various biological, chemical, and physical processes. It is essential in the body for digestion and excretion.
It also plays a crucial role in transporting nutrients and oxygen within the body.
Its ability to absorb a large amount of heat makes it ideal for use in cooling systems in industries and automobiles, and its high specific heat capacity makes it a good thermal store.