CIA Demonstration: The Paramagnetism of Oxygen (10.2.7)

Question 1

• Molecular orbital theory (MO theory) predicts the paramagnetism of oxygen due to unpaired electrons.

Answer 1

• Molecular orbital theory (MO theory) predicts the paramagnetism of oxygen due to unpaired electrons.

Question 2

• Valence bond theory has been superceded by molecular orbital theory since MO theory more closely describes what is observed.

Answer 2

• Valence bond theory has been superceded by molecular orbital theory since MO theory more closely describes what is observed.

Question 3

Bolts are aligned on a horseshoe magnet so that the
space is small enough to trap a pouring liquid. The
poles of the magnet are between the bolts.

No liquid nitrogen is caught and suspended
between the poles of a strong horseshoe magnet.
This is expected since liquid nitrogen is
diamagnetic.

A small amount of liquid oxygen is caught and
suspended between the poles of a strong
horseshoe magnet. It will hang there for a while and
then evaporate. This is expected since liquid oxygen
is paramagnetic.

Both valence bond theory and molecular orbital
theory predict that dinitrogen is diamagnetic (has no
unpaired electrons) and will not be attracted to the
poles.

Molecular orbital theory predicts that oxygen is
paramagnetic due to its two unpaired electrons.
Valence bond theory does not make that prediction.
When a theory doesn’t make the correct prediction,
it is superceded by a superior theory; one that does
explain an experimental observation.

Answer 3

Bolts are aligned on a horseshoe magnet so that the
space is small enough to trap a pouring liquid. The
poles of the magnet are between the bolts.

No liquid nitrogen is caught and suspended
between the poles of a strong horseshoe magnet.
This is expected since liquid nitrogen is
diamagnetic.

A small amount of liquid oxygen is caught and
suspended between the poles of a strong
horseshoe magnet. It will hang there for a while and
then evaporate. This is expected since liquid oxygen
is paramagnetic.

Both valence bond theory and molecular orbital
theory predict that dinitrogen is diamagnetic (has no
unpaired electrons) and will not be attracted to the
poles.

Molecular orbital theory predicts that oxygen is
paramagnetic due to its two unpaired electrons.
Valence bond theory does not make that prediction.
When a theory doesn’t make the correct prediction,
it is superceded by a superior theory; one that does
explain an experimental observation.