Module 4 - chapter 17 key terms

Question 1

Molecular ion

Answer 1

The positive ion formed from the loss of one electron from the original compound placed in the spectrometer. (M+ peak is found furthest right)

Question 2

Mass spectrometer

Answer 2

Detects the mass-charge (m/z) ratio of the molecular ion which gives the molecular mass of the compound.

Question 3

Fragmentation

Answer 3

In the mass spectrometer some molecular ions break down into smaller pieces know as fragments, this process is called fragmentation.

Question 4

Fragment ions

Answer 4

Cause the other peaks (aside from the M+ peak) in a mass spectrum.

Question 5

Wavenumber

Answer 5

Proportional to frequency, a more manageable scale. Any particular bond can only absorb radiation that has the same frequency as the natural frequency of the bond.

Question 6

Elemental anaylysis

Answer 6

Use of percentage composition data to determine the empirical formula.

Question 7

Mass spectrometry

Answer 7

Use of the molecular ion peak from a mass spectrum to determine the molecular mass; use of fragment ions to identify sections of a molecule.

Question 8

Infrared spectroscopy

Answer 8

Use of absorption peaks from an infrared spectrum to identify bonds and functional groups present in the molecule.