Lecture 5 & 6

Question 1

what is a condition for the two phases to coexist

Answer 1

for two phases to coexist, they need to be stable at the same pressure and temperature
this would imply that they would have equal gibbs free erngy because gibbs free energy is a function of pressure and temperature

Question 2

what is the condition for two phases to coexist if we have a pure component

Answer 2

their chemical potentials have to be equal. this is because chemical potential is a function of pressure and temperature and chemical potential for a pure substance is essentially the molar gibbs free energy

Question 3

what are the phase equilibrium conditions between two phases

Answer 3

the temperatures must be equal (no net transfer of heat),
the pressures must be equal ( no net transfer of heat)
the chemical potential must be equal ( no net transfer of mass)