Question

Indicate whether the following statements are true or false. Explain why

(a) The partial molar temperature, the partial molar volume, and the partial molar heat capacity are all proper partial molar quantities because the temperature, volume, and heat capacity are all extensive quantities.

(b) (4 points) ∆G and ∆ST ot can be seen to provide equivalent information about the sponteneity of a process. This is because ∆Ssys can be related to −∆H/T and ∆Ssurr can be related to −T∆S.

(c) ∆G is always equal to the non-expansion work done by a system.

(d) ∆H is always equal to the total work done by a system.

(e) Entropy plays a more important role in determining the spontaneous direction of a chemical reaction at lower temperatures than it does at higher temperatures.

Answer 1

1)False-Because though heat capacity and volume are extensive properties, temperature is intensive property.

2)False-S can be used to provide information about the spontaneity of a process provided it is an isolated system.

G=H-TS

G-Gibbs free energy H-Enthalpy S-Entropy T-Temperature

and Ssurr=-H/T and not TS

If del G is negative the process is spontaneous i.e del S has to be greater than del H at constant T and P. So the value of enthalpy is also important.

C)False-G is equal to non-expansion work by system at constant temperature and pressure only

d)False-H is always equal to total work done provided the pressure is constant and work is done on the system

e)False-If S>0 and H<0, the process will be spontaneous at high temperatures and non-spontaneous at low temperatures and when S<0 and H<0, the process will be spontaneous at low temperatures and non-spontaneous at high temperatures.