Asample containing anthracene dissolved in methane was separated using gas chromatography. methane was detected at 42.5 seconds (tm) and anthracene was detected at 173.6 seconds (tr). if the manufacturer of the column states that the volume of the mobile phase (vm) is 7.0 times the volume of the stationary phase (vs), calculate both the retention factor (k) and the partition coefficient (k) for anthracene in this separation.

1) k= ?

2) k= ?

a) k = 4.085

b) K = 0.143

Explanation:

gas chromatography:

∴ tm = 42.5 s

∴ tr = 173.6 s

∴ Vm = 7 Vs

a) retention factor (k):

∴ k = tr/tm

⇒ k = 173.6/42.5 = 4.085

b) partition coefficient (K):

∴ K ≅ Vs/Vm

⇒ K = 1/7 = 0.143

the electronic configuration of an atom with eight electrons is 1s²2s²2p⁴. the orbital diagrams are shown in the figure.

as per the hunds rule:

1. electrons tend to avoid being in the same orbital as per as practicable.

2. electrons in different orbitals of the same energy will have their spin parallel.

this can be illustrated from the multiplicity of the orbitals of the atom. as there are four electrons in the p orbital and p orbital has 3 sub-shells. the electrons can be fed in different ways as shown in the figure but the correct orbital diagram will be as per the hunds rule.