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).
If a gas is sufficiently dilute it obeys the ideal gas law. The ideal gas law can also be written. A molar quantity is indicated by the bar across the top. The ideal gas law is an equation of state. An equation of state relates the pressure, volume, and temperature of the gas given a quantity of n. moles of gas.