A gas barbecue grill uses propane gas. The propane is stored in a rigid tank. What happens to the pressure of the propane when the tank is left outside on a very hot summer day? What about on a cold winter day?
On a very hot summer day, the pressure of the propane will increase. On a cold winter day, the pressure of the propane will decrease.
Gay Lussac's law states that when volume is held constant, temperature and pressure are directly proportional, which means that when the temperature increases, so does the pressure.