What is Gay-Lussac’s Law?

Gay-Lussac’s Law is about how pressure and temperature work together inside a container that can’t change size.

Imagine you have a balloon filled with air, and it's sealed so it can't stretch or shrink, like when it's really full and tight. Now, if you put this balloon near a fire, the air inside gets hot. The molecules inside move faster and hit the sides of the balloon more often, making the pressure go up. That’s what Gay-Lussac’s Law is all about: when the temperature goes up, the pressure also goes up, as long as the volume stays the same.

Think about opening a can of soda on a hot day. The can is sealed and has a fixed size. The heat makes the gas inside expand, increasing the pressure until whoosh, it fizzes out! This is just like Gay-Lussac’s Law in action: temperature goes up → pressure goes up.

If you cool the balloon or soda can down, the opposite happens, the molecules slow down and hit the sides less often, so the pressure decreases. It's all about how hot or cold things get inside a fixed space!