C17 - Analysis Techniques

Question 1

Describe how a mass spectrometer works

Answer 1

1 – ionisation
Bombarded with electrons, knocks off electrons to make positive ions
2 – acceleration
Electric field accelerate or ions to same kinetic energy
3 - drift region
Heavier ions travel more slowly than lighter ions
4 – detector
Electric plate records charge due to ions. Time = of ions

Question 2

Describe how an infrared spectrometer works

Answer 2

Shine infrared at molecules and measure what is readmitted thus to work out what vibrational energy they use so what bonds they have (functional group)

Question 3

What is the fingerprint region

Answer 3

Region below 1500 on infrared spectroscopy, difficult to identify. Using a database to compare I can give you exact molecule