- A compound is a pure substance which contains two or more elements chemically combined together in a fixed proportion by mass. e.g. Na + Cl = NaCl
- The properties of a compound are entirely different from the properties of its constituents. E.g. water is a liquid while its constituents are gases.
- A compound is homogeneous in nature.
- The constituents of a compound cannot be separated by physical method.
- Light and heat are either evolved or absorbed during formation of a compound.
- Compound can also be classified into inorganic and organic on the basis of their structures. They can also be classified into acids, bases and salts on the basis of their properties.
Examples: Organic compound: Alcohol, ether, sugar,oil etc.
Inorganic compound: Calcium carbonate, carbon dioxide, sodium chloride etc.
Acids: sulphuric acid, nitric acid, hydrochloric acid etc.
Bases: Sodium hydroxide, Potassium hydroxide.etc.
Salts: Zinc sulphate, copper sulphate, ammonium chloride etc.
- Each compound has a fixed molecular formula, melting point and boiling point.