## The Third Law

Boltzmann Equation for Entropy: $S = k_{B} \ln W$

Hector Acosta Discussion 1H
Posts: 51
Joined: Fri Sep 29, 2017 7:04 am

### The Third Law

Can someone explain to me the third law of thermodynamics?

Cam Bear 2F
Posts: 60
Joined: Thu Jul 27, 2017 3:01 am

### Re: The Third Law

The third law of thermodynamics states that entropy of a perfect crystal is zero when the temperature is zero Kelvin. If it isn't a perfect crystal or if it is at a different temperature there will be residual entropy.

Cam Bear 2F
Posts: 60
Joined: Thu Jul 27, 2017 3:01 am

### Re: The Third Law

A perfect crystal only has one microstate so w=1. When you plug 1 into the equation S=kb*ln(w) and solve, you get zero.

Miguel Velasco 2J
Posts: 40
Joined: Fri Sep 29, 2017 7:07 am
Been upvoted: 1 time

### Re: The Third Law

we know the micro state is w=1 because there exists no movement at 0 Kelvin therefore resulting in entropy equal to 0.

Return to “Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy”

### Who is online

Users browsing this forum: No registered users and 1 guest