Which of the following is the correct R value to be used when the pressure is given in KPa? * 62.4 0.0821 8.314 273.15

Question

Which of the following is the correct R value to be used when the pressure is given in KPa? *

1) 62.4

2) 0.0821

3) 8.314

4) 273.15

Answer 1

When using the R constant, we want to use the value that has the same units of pressure as the pressure measurement. In the current example, that would be kilopascals (kPa). The following are the values of R with the different units of pressure:

R = 0.0821 Latm/Kmol (for atm)

R = 8.314 LkPa/Kmol (for kPa)

R = 62.36 Ltorr/Kmol (for torr)

So, the correct answer would be 8.314