Avogadro’s law tells about the relationship between the volume of a gas and the number of molecules possessed by it. It was formulated by an Italian scientist Amedeo Avogadro in 1811. During a series of experiments conducted by him, he observed that an equal volume of gases contains an equal number of particles. In other words, Avogadro’s law states that for an ideal gas, the volume of the gas is directly proportional to the number of moles possessed by it provided a constant temperature and pressure is maintained. This means that with an increase in volume, the number of moles will increase. Similarly, with a decrease in volume, the number of moles will also decrease. It is also known as Avogadro’s principle or Avogadro’s hypothesis. It is only applicable to ideal gases and gives an approximate result for the real gases. The gases with light molecules such as helium, hydrogen, etc., obey Avogadro’s law more accurately as compared to the gases with heavy molecules.
Examples
1. Breathing
Human lungs demonstrate Avogadro’s law in the best possible way. When we inhale, the lungs expand because they get filled with air. Similarly, while exhaling, the lungs let the air out and shrink in size. The change in volume can be clearly observed, which is proportional to the amount or the number of molecules of air contained by the lungs.
2. Inflating Balloon
To inflate a balloon, it is filled with air either through the mouth or with the help of a pump. If you decrease the amount of air contained by the balloon, a significant decrease in the volume or the size of the balloon can be observed. Hence, it follows Avogadro’s law.
3. Inflating Tyres
The shape of a flat tyre gets deformed in the absence of the required amount of air inside it. As soon as the flat tyre is filled with the required amount of air, the increased amount of air volume helps the flat tyre regain its original shape. Hence, the inflation of flat tyres is a clear demonstration of Avogadro’s law in everyday life.
4. Inflating a Ball
A soccer ball contains a bladder inside it and a rigid outer covering. When the ball gets deflated, the bladder gets deprived of air and loses its shape, thereby causing the ball to lose the ability to bounce. The volume of the air present inside the bladder can be increased by forcefully pressing air into it through an air pump. The change in volume of air is proportional to the change in the number of air molecules possessed by it. Hence, pumping air in a soccer ball is an explicit illustration of Avogadro’s law in real life.
5. Bicycle Pump Action
The action of a bicycle pump makes use of Avogadro’s law. The pump extracts the air from the environment and pushes it inside a deflated object. The increase in the number of gas molecules in the object correspondingly changes its shape and helps it to expand. This proportionality between the number of molecules of the air and the volume is nothing but Avogadro’s law.
6. Pool Tube
A deflated pool tube becomes portable as the decreased number of air particles inside the tube reduces its volume and makes it compact. During inflation, when the tube is filled with air, the number of air molecules inside it increases, thereby increasing the volume and size of the pool tube. Hence, Avogadro’s law can be implemented to inflate or deflate the pool tube as per the requirement.