Q.Name two items that can serve as a model for Gay Lussac's law and explain.

Gay-Lussac's law states that, at constant volume, the pressure of a fixed mass of gas is directly proportional to its Kelvin temperature:

Lines of constant volume on a pressure-vs-temperature graph are called isochores; a class activity confirms the law directly by recording the pressure of 1 mole of gas at six temperatures in two differently sized (but each individually fixed) containers, and finding pressure rises linearly with Kelvin temperature in both.

Everyday models and consequences. Because it is the amount of gas and its container that stay fixed while temperature drives pressure up or down, any sealed rigid container of gas is effectively a Gay-Lussac's-law demonstration: a car tyre (a nearly rigid volume of trapped air) shows measurably higher pressure on a hot day than a cold one, and a pressure cooker builds up internal pressure specifically because it is heated at essentially constant (sealed) volume. Aerosol cans carry an explicit heating warning for exactly this reason -- the propellant gas is sealed inside a fixed-volume metal can, so heating it (for instance by leaving it in a hot car or throwing it into a fire) drives its internal pressure up in direct proportion to the rise in Kelvin temperature, and past a certain pressure the can will rupture or explode. The same reasoning explains why an aerated-water bottle is kept under cool water in summer: keeping the trapped carbon-dioxide-plus-water-vapour mixture cool keeps its pressure from building past the point the bottle and its cap can safely contain.