# Nernst theorem

1. Mar 15, 2012

### matematikuvol

Entropy is defined by:

$$S(A)=\int^{T_A}_0C_V\frac{dT}{T}$$

where $$A$$ is state of the system in which temperature is $$T_A$$. When $$T_A\rightarrow 0$$ and $$C_V$$ must go to zero. Why? And how fast does it go?

Last edited: Mar 15, 2012
2. Mar 15, 2012

Your question is technically right but entropy is always increasing so it never be fall in zero.The 2nd law of thermodynamics says that (ds/dt)≥ 0. But may be in some special cases if externally keep the temperature very low depends on the state of the system its true and this is a very speedy process that is no interaction between the system and its surroundings so that the temperature is nearly= 0 and Cv falls into zero...