What is the R value for atmospheres in the gas constant?

The value of the gas constant, R, is critical in many gas law equations, including the ideal gas law, PV=nRT. When working with pressures measured in atmospheres, the correct value of R to use is 0.0821 Latm/molK. This value facilitates calculations involving ideal gases under standard conditions where pressure is expressed in atmospheres, volume in liters, and temperature in Kelvin.

Using this specific value of R ensures that all units are compatible in the ideal gas law equation, allowing for accurate calculations of variables such as pressure, volume, and temperature of gases. The other values listed correspond to different units of pressure (torr, bar) or energy (calories), making them unsuitable when working with pressures in atmospheres. Therefore, 0.0821 Latm/molK is the specific gas constant needed for calculations involving atm as the pressure unit.