all of them v.s all of whom

[lei.ji.privat]

The university graduates, all of them eager to get involved in..., volunteered to.. (Correct)

The university graduates, all of whom are eager to get involved in..., volunteered to.. (Correct)

Note the 2nd one has a verb "are", so whom should be used!

Can anyone explain why? and also I am often not sure that in which case the "be" verb should be used or simply just verb with be.ex. "eager to" vs. "are eager too"

[RonPurewal]

The university graduates, all of them eager to get involved in..., volunteered to.. (Correct)

The university graduates, all of whom are eager to get involved in..., volunteered to.. (Correct)

Note the 2nd one has a verb "are", so whom should be used!

Can anyone explain why? and also I am often not sure that in which case the "be" verb should be used or simply just verb with be.ex. "eager to" vs. "are eager too"

from what source are you getting these?
there are constructions somewhat similar to the first of these that are correct, but the first of these isn't ok.

please tell where you're getting this information, and we'll go from there; thanks.