W

[Andrew Hong]

How do you find the W for complex molecules and could I get an example please?

[Avantika MOhan_2B]

Do you mean in terms of entropy? Usually, the question gives you a clue about the orientations of the molecule or how many particles there are. The formula is just orientations ^ number of particles. So if we have a complex molecule, with multiple orientations (there's a good question about this in the textbook where they ask you to predict which entropy is higher looking at the molecule and the position of different elements in it), then we'd probably have a large entropy. Similarly, if we have a lot of particles - entropy could be high (but this depends on the value of orientations - it cant be 1).

[306052637]

You can find the degeneracy of a molecule by drawing the Lewis structure of the molecule and determining how many arrangements the molecule can be in, then raise it to the (number of moles times Avogadro's number) power.

An example given in class was BF2Cl, which is a trigonal planar structure. The Cl can be in any of the three places (since there are 3 outside atoms, the Cl can occupy any of the 3 spaces), so the energy state is 3. Then, raise 3 to the number of moles * the Avogadro's number to get the W. For example, 1 mol of BF2Cl would be W= 3^6.022*10^23.