Now,

(5.176)   (5.177)

Which is the equation of state of an ideal gas.
Considering Entropy,

(5.178)

Now,

Substituting in Eq. 5.178,

(5.179)

The molar entropy

(5.180)

This is known as the Sackur-Tetrode equation for the absolute entropy of a monoatomic ideal gas. It is seen that

(5.181)

where A stands for the sum of all terms that do not depend on T or V. This agrees with the equation from classical thermodynamics

(5.182)

Also,

(5.183)

and

(5.184)

These are the absolute values of the properties of a monoatomic ideal gas.