Nuclear Magnetic Resonance Concepts

What does the 'nuclear' part of NMR's name refer to?

• Nuclear power plants

• The nucleus of an atom

• Nuclear bombs

• Nuclear fusion reactions

Which type of atomic nuclei can be observed using Nuclear Magnetic Resonance (NMR)?

• Nuclei with an even number of protons

• Nuclei with odd mass numbers

• Nuclei with an even number of neutrons

• Nuclei that are radioactive

When a nucleus with a magnetic moment is placed in an external magnetic field, what happens to its alignment?

• It randomly changes direction

• It aligns itself with or against the magnetic field

• It stops spinning completely

• It repels the magnetic field

In NMR, what is 'resonance'?

• The sound made by the NMR machine

• The specific frequency of radio waves that causes nuclei to flip their spin

• The strength of the magnetic field used

• The temperature at which the sample is analyzed

What effect do electronegative atoms have on proton nuclei in an NMR spectrum?

• They shield the nuclei, shifting peaks to the right.

• They deshield the nuclei, shifting peaks to the left.

• They have no effect on the nuclei.

• They cause the nuclei to disappear from the spectrum.

If a proton is next to a carbon with 3 adjacent protons, how many times will its peak be split according to the n+1 rule?

• 2

• 3

• 4

• 5

Why are OH protons considered "tricky" in an NMR spectrum?

• They always appear as a triplet.

• They can swap with other protons and appear as unsplit peaks anywhere.

• They are always highly shielded.

• They only appear in aromatic compounds.

A single proton peak appears around 12 PPM in an NMR spectrum. What functional group is likely present?

• Alkene

• Aldehyde

• Carboxylic acid

• Benzene