Profile
Settings
Refer your friends
Sign out
Avogadro’s law, also known as the Avogadro hypothesis, is a gas law that relates the volume of gas to the amount of gas substance present. The law is an example of the ideal gas law in action. As per Avogadro’s theory, equal volumes of all gases have equal numbers of molecules at the same pressure and temperature. If pressure and temperature remain constant, the volume and amount of an ideal gas are directly proportional to its mass. Avogadro’s law was coined by Amedeo Avogadro, who proposed in 1812 that two identical samples of an ideal gas with equal volume, temperature, and pressure have the same number of molecules. When equal amounts of gaseous nitrogen and hydrogen are at the same pressure and temperature, they contain an identical number of atoms and exhibit perfect gas behaviour. In actuality, real gases deviate slightly from the ideal behaviour, therefore, the law only holds roughly, but it is still a useful estimate for scientists.
Avogadro’s Law
The link between the volume of gas and the number of moles is known as Avogadro’s law. This law asserts that the total number of molecules or atoms contained in a gas is directly proportional to the volume occupied by that gas at constant temperature and pressure.
The mathematical formula for Avogadro’s law is given by:
V ∝ n
V=kn or k = V/n
In the above equation,
V represents a volume of gas
n represents a number of moles present in a given gas
k represents proportionality constant
Examples of Avogadro’s Law
Breathing: Breathing is an excellent example of Avogadro’s law. Because our lungs are filled with air as we inhale, they expand. However, when we exhale, we allow the air out of our lungs, which causes them to shrink in size. The amount or number of air molecules of air in the lungs causes a change in volume, which is proportional to the amount or number of air molecules in the lungs.
Inflation Tyre: In the lack of air, the shape of a flat tyre becomes distorted. Flat tyres return to their original shape as soon as they are filled with the proper amount of air. As a result, the inflation of flat tires is a practical application of Avogadro’s law.
Pumping a Bicycle Tyre: The pump draws air from the surrounding environment and forces it into a flattened object. This increase in the number of molecules of gas in an item alters its form and aids its expansion. Avogadro’s law clearly explains this scenario.
Inflation/Deflation of a Pool Tube: A flattened pool tube becomes transportable when the quantity of air molecules inside the tube decreases, resulting in a reduction in volume and compactness. When the pipe is filled with air during inflation, the number of air molecules in the tube grows, increasing the volume and size of the pool tube. As a result, we can use Avogadro’s law to deflate and inflate the supplied pool tube as needed.
The Compression of Gas
Gas volume reduces as pressure rises because gas particles are pushed closer together. When pressure on a gas lowers, the volume of gas increases because the gas molecules may now move wider apart. Because this volume of gas has grown as the weather balloon rises through the environment to lower pressure regions, the gas inside the balloon expands until external and internal pressures are equal.
Significance of Avogadro’s Law
This formula developed a vital relationship for simple molecules when the difference between atoms and molecules was not visibly known after recognising that the volume of gas directly correlates to the number of particles in the gaseous molecules. The presence of diatomic molecules like O2, Cl2, and H2 was not discovered until findings on the volume of gas particles were discovered.
Conclusion
Avogadro’s law, also known as the Avogadro hypothesis, is a gas law that relates the volume of gas to the amount of gas substance present. The law is an example of the ideal gas law in action. As per Avogadro’s theory, equal volumes of all gases have equal numbers of molecules at the same pressure and temperature. If pressure and temperature remain constant, the volume and amount of an ideal gas are directly proportional to its mass. Gas volume reduces as pressure rises because gas particles are pushed closer together. When pressure on a gas lowers, the volume of gas increases because the gas molecules may now move wider apart.
