Modern Analytical Techniques

Question 1

Effect of infrared radiation on molecules

Answer 1

When absorbed, causes covalent bonds to vibrate

Question 2

How modern breathalysers work

Answer 2

Measure ethanol in breath by analysis with infrared spectroscopy

Question 3

Use of mass spectrometry

Answer 3

• determining relative isotopic masses of elements

- identifying elements (e.g. in the mars space probe, or monitoring environmental pollution levels, e.g. lead)

Question 4

Fragmentation (mass spectrometer)

Answer 4

The process in mass spectrometry that causes a positive ion to split into pieces, one of which is a positive fragment. From left over energy from electron impact

Question 5

Where is the M+ peak found

Answer 5

Farthest to the right (careful of a very tiny peak next to it - could be isotopes)

Question 6

How can mass spectra of molecules be used

Answer 6

Mass spectra will show peaks at specific points, depending on what bonds are more likely to break. Therefore, they can be used as fingerprints to identify the molecule using a spectral data base