When to use R

[jadyndavidson]

Hi! Can anyone explain which R value we are supposed to use when solving for n in PV=nRT?

[Sophia Peavy Lec 1]

Hi it should just be the 8.3145 value typically, but you use any R value that cancels out the other units in your problem.

[Damin Rawlins 3B]

Use the gas constant (R) that corresponds to the units of pressure, volume, temperature, and the amount of substance (n). If pressure is in atm, volume is in L, and temperature is in K, use R=0.0821 L x atm/mol x K. If pressure is in Pa, volume is in m^3, and temperature is in K, use R=8.314 J/mol x K. Ensure that all units in the equation are consistent with the units of R used to obtain the correct value of n.

[michelle vooskanian 3F]

in the ideal gas law equation PV=nRT, the variable n represents the number of moles of gas. the ideal gas constant R depends on the units you are using for pressure, volume and temperature. make sure that the units you are using for pressure, volume and temperature are consistent with the units of the gas constant R.
the values for R would be:
R=0.0821 kPa-1 mol-1 K-1 (used when pressure is in kilopascals, volume is in liters, and temperature is in kelvins)
R=0.0821 L atm-1 mol-1 K-1 (used when pressure is in atmospheres, volume is in liters, and temperature is in kelvins)
R=9.314 J mol -1 K-1 (used when pressure is in pascals, volume is in cubic meters, and temperature is in kelvins)