Unit 2- Mass spectra and IR

Question 1

How can molecules absorb IR radiation?

2.12.c

Answer 1

• The bonds within the molecule must be polar
• Can be from the bond vibrating, stretching or bending
• Diatomic molecules cannot absorb IR as their electronegativies are the same therefore no polar bond

Question 2

What is the highest peak in a mass spectrum?

2.12.a

Answer 2

• The parent ion
• It is the relative molecular mass

Question 3

What are the peaks in a mass spectrum?

2.12.a

Answer 3

• Fragments of the parent ion
• The fragments make up the parent ion

Question 4

Name some greenhouse gases

Answer 4

• H₂O (g)
• CH₄
• NO
• CO₂