- For a pure substance undergoing vaporization, the change in Gibbs free energy is negative, indicating that the process is spontaneous under normal conditions.
Conclusion: The change in Gibbs free energy for vaporization is negative, as given by option (B).
A closed-loop system has the characteristic equation given by: $ s^3 + k s^2 + (k+2) s + 3 = 0 $.
For the system to be stable, the value of $ k $ is: