Final answer:
Propane tanks are typically filled to about 80% capacity to allow a 20% buffer space for the expansion of gas, which prevents overpressure. This precaution is based on Gay-Lussac's Law and prevents the possibility of leaks or tank ruptures due to temperature changes.
Step-by-step explanation:
In the context of the safety of pressurized containers like propane tanks, it's essential to reserve a certain percentage of their capacity to allow for the expansion of the gas inside. These precautions are taken to prevent the dangers of overpressure, which can lead to leaks or even the rupture of the tank. This concept is related to Gay-Lussac's Law, which states that for a given mass and constant volume of an ideal gas, the pressure exerted on the sides of its container is directly proportional to its absolute temperature.
The exact percentage of capacity reserved to prevent overpressure due to expansion can vary based on the design of the tank and the expected temperature range in which it will be used. However, a common industry standard is to fill propane tanks to only about 80% of their capacity.
This 20% reserve allows the propane, which is stored as a liquid in the tank, to expand and becomes gas as temperatures rise. It's why pressure may register higher on a hot day, and temperature considerations must be made when checking pressure gauges. Failure to leave adequate space for expansion could result in leaks or tank bursts, as solids and liquids resist compression, exerting large forces against constriction.