Avogadro’s Law is a fundamental principle in chemistry that describes the relationship between the volume of a gas and the number of gas particles (moles) when temperature and pressure are kept constant. It states:
“Equal volumes of all gases, at the same temperature and pressure, contain the same number of molecules.”
In simpler terms:
- If you increase the number of gas particles, the volume increases proportionally, as long as temperature and pressure do not change.
- Conversely, if you decrease the number of gas particles, the volume decreases proportionally.
Mathematically, it is expressed as: V∝n
where:
- V = volume of the gas
- n = number of moles of the gas
Key points to remember:
- Temperature and pressure must remain constant.
- It explains why gases expand to fill their containers.
- It is the basis for understanding the molar volume of a gas, which is 22.4 liters at standard temperature and pressure (STP).