# How do you calculate microstates in chemistry?

##### 1 Answer

Well, you can calculate the NUMBER of microstates at

- I go over what microstates are, here.
- An example that should be easy to follow is here.
- A much more detailed calculation example with methane is gone into here.

**Boltzmann's formulation of entropy** states:

#S = k_BlnOmega# where

#Omega# is the number of microstates, and#k_B = 1.38065 xx 10^(-23) "J/K"# is the Boltzmann constant.

There is a more complicated formula for

#Omega = "exp"{sum_(i=1)^(N) [N_iln(g_i/N_i) + N_i]}# where

#N_i# is the number of particles with energy#epsilon_i# in a state with degeneracy#g_i# .

For simplicity, we can calculate the value of

#Omega = e^(S//k_B) = "exp"(S//k_B)#

As an example,

#color(blue)(Omega) = "exp"((205.15 cancel"J""/"cancel"mol"cdotcancel"K")/(1.38065 xx 10^(-23) cancel"J""/"cancel"molecule"cdotcancel"K" xx (6.0221413 xx 10^(23) cancel"molecules")/(cancel"1 mol")))#

#= color(blue)(5.197 xx 10^10)#

So, there are