Spectroscopy And Spectrometry

Question 1

What is basic property needed for NMR?

Answer 1

Uneven number of protons and neutrons

Question 2

Alignment of nuclei with or against magnetic field?

Answer 2

Higher: against field
Lower: with field

Question 3

Upfield vs downfield

Answer 3

Upfield: shielded by e- density

Downfield: deshielded

Question 4

Where are aromatic compounds on NMR spec?

Answer 4

Middle due to electron delocalization from structure

Question 5

What is the basis of mass spec?

Answer 5

uses magnetism as well

Question 6

How is mass spec done?

Answer 6

Ionization with e-beam

- can break molecules into pieces

Question 7

What is parent ion

Answer 7

Generated by loss of only one electron (M+)

Question 8

What is the process of mass spec using the force generated by molecules through magnetic field?

Answer 8

F = qvBsin theta

• why we need to put through electric field to first ionize
• shape: how deflected is determined by charge and indirectly mass (influences velocity)

Question 9

Parent peak = molecular weight

Answer 9

• far right, highest m/z = M+ (same weight with +1 charge)

Question 10

Largest peak on mass spec

Answer 10

• most common ion present, clues how to break apart