Question

1. A hydrocarbon with six carbon atoms exhibitsa proton NMR spectrum with several peaks in the 1.0 - 2.0 ppmchemical shift range in addition to several peaks in the 6.0 ppmchemical shift range. What is most likely the identity of thismolecule?
a. 4-methylpent-1-yne
b. hexane
c. 3-methylpent-2-ene
d. hexyne

2. The gas phase IR spectrum of butan-1-olexhibits a sharp band at approximately 3500 cm-1, while in theliquid phase the same molecular vibration exhibits a broad band atapproximately 3000-3400 cm-1. The best explanation for thisobservation is:
a. Butan-1-ol has a lower temperature in the liquid phase comparedto the gas phase.
b. Hydrogen bonding interactions in the liquid phase result in abroad range of vibrational frequencies for the -OH stretchmode.
c. The higher density of molecules in the liquid phase compared tothe gas phase cause the IR band to broaden.
d. Butan-1-ol isomerises to butan-2-ol in the liquid phase.

3. How many unique chemical environments can beidentified using proton NMR spectroscopy for the hydrogen atoms inpentan-2-one?