Extra information/ gaps to fill

Question 1

**H1 NMR **

What is simplified splitting and what does it tell you?

Answer 1

• Pascals triangle i.e.,
• 1:1= doublet peak= 1 neighbour
• 1:2:1= triplet peak= 2 neighbours

Question 2

H1 NMR
Pros and cons
What is the sample dissolved in for analysis

Answer 2

Pros: non-destructive, rapid, cheap, easy sample preparation

Cons: Expensive instrument, limited qualitative results

Sample dissolved in solvent like D2O

Question 3

H1 NMR

What is the equation for Larmore frequency?

Answer 3

Larmor frequency= B0 x gyromagentic ratio

Question 4

Mass spectrometry

Pros and cons of this method

Answer 4

Pros: used for both qualitative and quantitative analysis, sensitive, find structure of unknown compounds

Cons: cannot separate optical and geometrical isomers, hydrocarbons which produce similar ions are not identified

Question 5

IR
wavelength (nm)
Pros and cons

Answer 5

700-1000nm

Pros: non-destructive, no preparation, sensititivty

Cons: doesnt give detail on functional group location, impossible to determine substance molecular weights, no adherence to beer law is frequence occurance

Question 6

UV/Vis spectroscopy

Vis and UV region in nm on the electromagnetic spectrum

Answer 6

Vis: 400-750nm
UV: 100-400nm

Question 7

UV/Vis spectroscopy

When referring to the change in energy between p orbitals with conjugation, what symbols are used to describe these energy changes in single and double bonds

Answer 7

single bonds: σ - σ*
Double bonds: π - π