HNMR

1. What does NMR stand for?

• Nuclear Magnetic Resonance

• Nuclear Molecular Rotation

• Natural Magnetic Radiation

• Neutron Mass Ratio

What happens when a nucleus in an NMR spectrometer absorbs radio wave energy?

•  It splits into multiple nuclei

• It moves to an anti-parallel position relative to the magnetic field

•  It begins to emit gamma radiation

• It fuses with nearby nuclei

Which of the following isotopes is NOT commonly used in organic chemistry NMR?

• Hydrogen-1

• Carbon-13

• Carbon-12

• Deuterium

What is the purpose of adding tetramethylsilane (TMS) to an NMR sample?

• To increase the sample's solubility

  
  

• To provide a reference peak at 0 ppm

• To split peaks into multiplets

• To increase the magnetic field strength

What information does peak splitting provide in proton NMR?

• The number of carbons in the molecule

• The number of oxygens in the molecule

• The number of adjacent protons

• The molecular mass of the compound

What is the "N+1 rule" in NMR spectroscopy?

• The number of peaks equals the number of protons plus one

• The number of split peaks equals the number of adjacent protons plus one

• The chemical shift value equals the number of carbons plus one

• The integration value equals the number of hydrogens plus one

Why might a peak in an NMR spectrum appear outside its expected chemical shift range?

• The spectrometer is malfunctioning

• The sample is impure

• The molecule contains unusual isotopes

•  The atom is influenced by nearby functional groups

What is the purpose of adding D₂O (heavy water) to an NMR sample?

•  To increase the solubility of the sample

• To provide a reference peak

• To identify and remove OH and NH₂ peaks

• To increase the magnetic field strength