15E.8

Question 1

what are the two features that 1H NMR LR AND 1H NMR HR agree own

Answer 1

1. peaks at different chemical shifts help identify the different chemical environments of hydrogen atoms
2. the relative peak areas (the ratio of peak area) help us decide the number of hydrogen atoms responsible for the peak

Question 2

what are equivalent protons

Answer 2

they are hydrogen atoms on the same chemical environment

Question 3

what is the extra feature that 1H NMR HR has that 1H NMR LT doesn’t have

Answer 3

a splitting pattern

Question 4

what is a splitting pattern

Answer 4

it is the appearance of a peak as a small number of small sub-peaks that are very close to each other

Question 5

for splitting pattern the chemical shift

Answer 5

located in the centre of the group of sub-peaks

Question 6

the relative area of 1H NMR HR is shown by

Answer 6

an integration trace, or by showing the number next to the peaks

Question 7

the relative area indicates

Answer 7

the ratio of the number of protons, so its not always the real value

Question 8

what causes the splitting of the peaks

Answer 8

the influence that comes form the protons (hydrogen atoms) attached to the adjacent carbon

Question 9

the splitting of the peaks is referred to as

Answer 9

(spin-spin coupling)

Question 10

what is the n + 1 rule

Answer 10

if a carbon has n protons, then the peaks on the adjacent carbon will be split into n + 1 sub-peaks (multiples)

Question 11

what are multiples

Answer 11

the different splitting patterns observed (singlets, doublets, triplets. quartets) in a HR 1H NMR spectrum

Question 12

if a peak is not split it is called a

Answer 12

singlet

Question 13

if a peak is split to two sub peaks it is called

Answer 13

doublet

Question 14

if a peak is split into 3 sub peaks its called

Answer 14

triplet

Question 15

if a peak is split into 4 sub peaks it is called

Answer 15

quartet

Question 16

what are the shapes of multiples

Answer 16

table A page 151

Question 17

the splitting of a group of protons only indicate

Answer 17

the number of protons on the adjacent carbon, and noting about the group of protons being split

Question 18

analysis of the spectrum of butanone

Answer 18

page 151 table B

Question 19

a molecule that is completely symmetrical doesn’t have a

Answer 19

splitting pattern that is because neither carbon group would effect each other since they are equivalent

Question 20

when a peak is split to 5 sub-peaks we call it

Answer 20

a quintet

Question 21

when a peak is split to 6 sub-peaks we call it

Answer 21

sextet

Question 22

if a proton is attached to two different adjacent protons what would the effect be on it