101
Discussion Chem Board for Science Salon
O2 vs. N2
So, liquid N2 and liquid O2 were both poured over a magnet. The liquid N2 poured right
through. The liquid O2 was attracted to the magnet and was held between the poles of the
magnet until it evaporated. Now what you may not know is that paramagnetism is a
property of materials that have unpaired electrons.
1. Fe is magnetic. Draw the electron configuration of Fe in an orbital diagram.
How many unpaired electrons does Fe have?
2. Draw the Lewis structures of N2 and O2. How many unpaired electrons do they
have?
3. We have seen that Lewis structures dont always give us the best representations
of molecules. This is example another where the actual property of a molecule is
not represented well by a Lewis structure. Molecular orbital theory is a different
theory of orbitals and bonding than the bonding theory we have been discussing
in class. Below are the molecular orbitals for N2 and O2 in this other theory. (I
know weird huh.) Put valence electrons in the orbitals for N2 and O2. How many
unpaired electrons do they have?
N2
__
2s
__
*2s
__
2p
__ __
2p
__ __
*2p
__
*2p
O2
__
2s
__
*2s
__
2p
__ __
2p
__ __
*2p
__
*2p
4. Any comments on the ping-pong ball of flame? How would the fire have
compared if we had immersed the ball in N2, instead of O2?
Thank you Ashley!