The value of the gas constant R in SI units can be obtained by converting calories to joules. Given that
1 cal = 4.184 J, we can calculate the value of R in joules per mole per Kelvin (J/(mol·K)).
Starting with the value in calories:
R = 1.987 cal/(mol·K)
Now, we convert this to joules:
R = 1.987 cal/(mol·K) × 4.184 J/cal
R ≈ 8.314 J/(mol·K)
Thus, the value of the gas constant R in SI units is approximately 8.314 J/(mol·K).