What is the relationship between gas pressure and volume?

Gas pressure and volume have an inverse relationship, as described by Boyle's Law.

Boyle's Law, named after physicist Robert Boyle, is a fundamental concept in gas physics. It states that the pressure and volume of a gas have an inverse relationship when held at a constant temperature. This means that as the volume of a gas increases, its pressure decreases and vice versa.

Imagine a balloon filled with air. The air molecules inside the balloon are constantly moving and colliding with the walls of the balloon, creating pressure. If you were to squeeze the balloon, reducing its volume, the same amount of air molecules would be confined to a smaller space. This would result in more frequent collisions with the balloon walls, thus increasing the pressure. Conversely, if you were to inflate the balloon further, increasing its volume, the air molecules would have more space to move around. This would result in fewer collisions with the balloon walls, thus decreasing the pressure.

This relationship can be mathematically expressed as P1V1 = P2V2, where P1 and V1 are the initial pressure and volume, and P2 and V2 are the final pressure and volume. This equation shows that the product of the initial pressure and volume is equal to the product of the final pressure and volume, further illustrating the inverse relationship between pressure and volume.

Understanding Boyle's Law is crucial in many areas of physics and engineering, including understanding how gases behave under different conditions, predicting the behaviour of gas in a closed system, and designing equipment that uses gases, such as engines and pneumatic systems.