Gases and the Gas Laws: an Introduction
How pressure, volume and temperature of a gas pull on one another
Big idea: A gas has no shape and no fixed volume of its own — it fills whatever container you put it in. Its state is described by just three quantities: pressure (p), volume (V) and temperature (T). Change one, and the others usually change too. The gas laws are simple rules that say exactly how.
By the end you will be able to:
- describe a gas with the three quantities p, V and T, in SI units;
- explain, using moving molecules, why a gas pushes on its walls;
- convert a Celsius temperature to the Kelvin (absolute) scale;
- state Boyle's law, Charles's law and Gay-Lussac's law in words and as formulas;
- predict which way p or V changes when you squeeze or heat a gas.