Exam 12: Infrared Spectroscopy and Mass Spectrometry

The IR spectrum of a sample contains absorptions at 3050, 2950, and 1620 cm^-1. To what class of organic compound does this sample most likely belong?

Explain the following observation regarding the IR stretching frequencies of the ketones shown below.

Using IR, how could you tell if the reaction below was complete?

Which of the indicated bonds would be expected to have IR active frequencies?

Which compound has a strong and broad IR absorption centered at 3400 cm^-1?

Describe the molecular ion region in the mass spectrum of CH₃CH₂Br.

A nonlinear molecule with n atoms generally has ________ fundamental vibrational modes.

Absorption of what type of electromagnetic radiation results in electronic transitions?

For toluene (shown below), you would expect to see which m/z fragment in the mass spectrum?

In addition to a carbonyl stretch, which of the following molecules exhibits two characteristic stretches at 2700 and 2800 cm^-1?

Which has the higher speed in a vacuum, ultraviolet or infrared light?

Which of the following would not have a C-H stretch at about 3050 cm^-1?

Arrange the following regions of the electromagnetic spectrum in order of increasing wavelength: X ray, radio, UV, and IR.

Describe the fate of a molecule from introduction to detection in a mass spectrometer.

Which of the following structures is consistent with the IR spectra shown below?

Which region of the electromagnetic spectrum, IR or UV, contains photons of the higher energy?

Arrange the following IR bond stretches in order of increasing wavenumber: C-O, C C, O-H, and C=C.

At approximately what wavenumber does one expect to find the carbon-carbon triple bond stretch in the IR spectrum of an alkyne?

What IR absorption is characteristic of the O-H stretch in alcohols?

The wavelength and frequency of a given wave of electromagnetic radiation are ________ proportional.