Chapter 13 lecture

Question 1

What does Mass Spectrometry do

Answer 1

Determines molecule weight and molecule formula of a compound

Question 2

What is Mass Spectrometry

Answer 2

Molecule Vaporized and ionized by bombardment with beam of high energy electrons

Question 3

What does the electron beam do when using mass spectrometry?

Answer 3

causes a molecule to eject electron

Question 4

What does the Mass spectrometer make?

Answer 4

radicals and cations

Question 5

What is the tallest peak

Answer 5

Base peak

Question 6

Nitrogen rule

Answer 6

odd molecular ions contain odd number of N while even number of N have even molecular ions

Question 7

Alkyl chloride special

Answer 7

3:1 ratio for molecular ion

Question 8

Alkyl bromides

Answer 8

1:1 ratio for molecular ion

Question 9

What does a large molecule mean for fragments

Answer 9

more fragments

Question 10

Aldehydes certain fragmentation patterns

Answer 10

alpha cleavage: Next to C with O on it

Question 11

Ketones certain fragmentation patterns

Answer 11

alpha cleavage: Next to C with O on it

Question 12

Alcohols certain fragmentation patterns

Answer 12

alpha cleavage and dehydration (elimination of water)

Question 13

Infrared Spectroscopy

Answer 13

used to identify bonds and functional groups in compound

Question 14

discuss wavelength and frequency

Answer 14

inversely proportional
Wavelength increase= frequency decreases

Question 15

What happens when IR light is absorbed by bonds

Answer 15

2 atoms a bond can stretch and 3 bonds can bend

Question 16

How to know if IR light is absorbed

Answer 16

frequency of bond stretching matches frequency of IR so light is absorbed

Question 17

What is the functional group region

Answer 17

4000-1500 wavenumber

Question 18

what is the fingerprint region

Answer 18

1500 and down

Question 19

What is wavenumber proportional to

Answer 19

frequency

Question 20

X axis of IR

Answer 20

wavenumbers

Question 21

Y axis of IR

Answer 21

transmittance

Question 22

100% vs 0% transmittance

Answer 22

100% all light went through sample
0% all light absorbed

Question 23

What properties affect IR absorption

Answer 23

bond strength and atom mass

Question 24

Stronger bonds

Answer 24

higher frequency

Question 25

lighter atoms

Answer 25

higher frequency

Question 26

4000-2500 wavenumber

Answer 26

bonds to hydrogen

Question 27

2500-2000

Answer 27

triple bonds

Question 28

2000-1500

Answer 28

double bonds

Question 29

1500-400

Answer 29

single bond/ fingerprint region

Question 30

how does s character affect IR

Answer 30

higher s character % means stronger bond means higher wavenumber

Question 31

O-H wavenumber and intensity

Answer 31

3600-3200 and strong/broad

Question 32

N-H wavenumber and intensity

Answer 32

3500-3200 and medium

Question 33

Csp3-H wavenumber and intensity

Answer 33

3000-2850 and strong

Question 34

Csp2-H wavenumber and intensity

Answer 34

3150-3000 and strong

Question 35

Csp-H wavenumber and intensity

Answer 35

3300 and medium

Question 36

C triple C wavenumber and intensity

Answer 36

2250 and medium

Question 37

C triple N wavenumber and intensity

Answer 37

2250 and medium

Question 38

C=O wavenumber and intensity

Answer 38

1800-1650 and strong

Question 39

What does the increase of s character do to the wavenumber

Answer 39

increase the wavenumber

Question 40

For IR absorption to work what must a molecule have?

Answer 40

dipole moment