Gunpowder's burning rate increases with pressure, so it will burst containers but just burns in the open. Ignition of the powder packed behind a bullet must generate enough pressure to force it from the muzzle at high speed, but not enough to rupture the gun barrel.
The gas constant occurs in the ideal gas law, as follows: where P is the absolute pressure (SI unit pascals), V is the volume of gas (SI unit cubic metres), n is the amount of gas (SI unit moles), m is the mass (SI unit kilograms) contained in V, and T is the thermodynamic temperature (SI unit kelvins).
Students are often confused by the units of the ideal gas constant. there are two forms of the gas constant: the universal gas constant and the specific gas constant. confusion and error, these are defined below, along with their relationships with mol and molecular weight.