Final answer:
An LP gas cylinder can burst when heated in a flame due to the increased pressure from rising temperatures, as described by Gay-Lussac's Law. The pressure may exceed the cylinder's capacity, leading to a burst, especially if the gas is combustible.
Step-by-step explanation:
An LP gas cylinder may burst when placed inside a flame due to the rapid increase in pressure inside the cylinder caused by heating. As per Gay-Lussac's Law, the pressure of a gas is directly proportional to its temperature at a constant volume.
Thus, when an LP gas cylinder is heated, as in when it is placed inside a flame, the temperature of the gas increases which, in turn, causes a sharp increase in pressure. If the pressure exceeds the capacity of the cylinder, it can result in the cylinder bursting. Additionally, gases like isobutane are combustible, adding to the risk of explosion upon incineration.
Real-world examples, such as the explosion of a sealed can of soup heated over a campfire or the change in readings of a propane tank gauge depending on temperature, illustrate this principle. Moreover, the kinetic-molecular theory explains that as the gas molecules are heated, they move faster and collide more forcefully with the walls of the container, further increasing pressure.
If no safety measures are in place, such as air gaps or pressure relief valves, this increased pressure could lead to a rupture.