* The universal gas constant (R): You mentioned using a universal constant, but you didn't specify which one. The most common values for R are:
* 8.314 J/(mol·K) (SI units)
* 0.0821 L·atm/(mol·K) (using liters and atmospheres)
* The units you want the pressure in: Do you want the pressure in Pascals (Pa), atmospheres (atm), or some other unit?
Once you provide this information, I can calculate the pressure of the natural gas using the ideal gas law:
PV = nRT
where:
* P = pressure
* V = volume (20 liters)
* n = number of moles (4 moles)
* R = universal gas constant
* T = temperature (274 K)
