Question 4G.5

[905960080]

Considering positional disorder, would you expect a crystal of octahedral cis - MX2Y4 to have the same, higher, or lower residual entropy than the corresponding trans isomer? I understand that we are supposed to use the equation S = kB ln (W) to calculate the entropy. and for W we should use the possible positions raised to avogadros number. For the cis-MX2Y4, there are 12 positions per molecule but for the trans-isomer, there are 3. Does anyone know how were supposed to know how many positions these two molecules have?

[Brandon Zhang 3E]

For 1 mole, W is the number of possible orientations raised to the power of Avagadro's number. If you are given the amount of atoms, you do the same thing but replace Avagadro's number with the number of atoms.