What is the R value for torr when using the gas constant?

The R value, or the ideal gas constant, represents the relationship between pressure, volume, temperature, and the number of moles in an ideal gas equation. When using torr as the unit of pressure, the appropriate value for the gas constant is 62.4 Ltorr/mol·K.

This value is derived from the relationships among different gas constants, where the units must appropriately reflect the conditions being described. For instance, when pressure is measured in atmospheres, a commonly used gas constant value is 0.0821 Latm/mol·K. Similarly, if pressure is measured in kilopascals, the value changes to 8.31 LkPa/mol·K.

The choice that includes 1.987 cal/mol·K represents energy-related constants rather than the ideal gas law, making it unsuitable for this context. Each of these values is useful when engaging with the ideal gas law under different conditions, thus highlighting the importance of using the correct constant based on the units of measurement. Therefore, when working with torr, 62.4 Ltorr/mol·K is the correct gas constant to use.