Water
Definition and meaning of Water in chemistry.
Water is a crucial chemical compound consisting of two hydrogen atoms covalently bonded to one oxygen atom. It acts as the universal solvent and is absolutely essential for all known forms of life. This simple molecule displays unique chemical properties that shape the physical environment of our entire planet.
In more detail
Oxygen has a much higher electronegativity than hydrogen, meaning it pulls shared electrons toward itself. Because of this unequal sharing, water molecules are highly polar with distinct partial electrical charges. The oxygen atom carries a partial negative charge, while the hydrogen atoms carry partial positive charges.
This built-in polarity allows neighboring water molecules to form strong electrostatic connections called hydrogen bonds. This extensive hydrogen bonding network gives liquid water several highly unusual physical and chemical properties. It has an exceptionally high boiling point compared to similar molecules of the same size.
Water also has a very high specific heat capacity, meaning it absorbs vast amounts of thermal energy. A common student misconception is that water conducts electricity perfectly on its own. Pure water is actually an excellent insulator and does not conduct electrical current well at all.
It only conducts electricity when dissolved ionic salts are freely floating within the liquid mixture. As a highly effective solvent, water effortlessly dissolves many ionic compounds and polar organic molecules. This dissolving power facilitates critical biochemical reactions and nutrient transport processes inside living biological cells.
Key facts
| Field | General Chemistry |
|---|---|
| Chemical Formula | H2O |
| Molecular Geometry | Bent |
| Bond Angle | Approximately 104.5 degrees |
| Primary Intermolecular Force | Hydrogen bonding |
When solid sodium chloride dissolves in water, the highly polar water molecules attack the crystal lattice. The partially negative oxygen atoms immediately surround and attract the positively charged sodium ions. Meanwhile, the partially positive hydrogen atoms surround and pull away the negatively charged chloride ions. This coordinated molecular action physically separates the ions and disperses them evenly throughout the liquid. This basic chemical process explains why the salty oceans exist and how our bodies process minerals.
Frequently asked questions
Why does solid ice float on top of liquid water?
Ice floats because its crystal structure spaces the water molecules further apart. This rigid open arrangement makes solid ice less dense than liquid water.
Why is water frequently called the universal solvent?
Water dissolves more chemical substances than any other known liquid on Earth. Its strong polarity allows it to pull apart many ionic and polar compounds.
How do hydrogen bonds affect the boiling point of water?
Hydrogen bonds tightly hold neighboring water molecules together in the liquid phase. You must add significant heat energy to break these bonds and boil the water.
Related terms
Sources & references
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