Analytical Technique

Question 1

what is wavelength

Answer 1

distance between adjacent peaks of electric field

Question 2

what is wave number directly proportional to

Answer 2

energy

Question 3

formula for transmittance

Answer 3

T=1/I0 *100

Question 4

formula for absorbance

Answer 4

A=-log (1/10)

Question 5

bond stretching will increase if …….. is increases

Answer 5

amplitude

Question 6

what are the principles of IR

Answer 6

• Quantum theory
• molecules only absorb energy as a quantum that corresponds to energy difference between 2 different energy levels
• energy of IR radiation will allow the molecules to transfer between states

Question 7

what is quantum theory

Answer 7

molecules and atoms can only exist on certain energy levels

Question 8

for a bond to absorb IR there must be a …… ………

Answer 8

dipole moment

Question 9

energy states from lowest to highest

Answer 9

sigma - bond e- 
pie - bond e-
pie- lone pair e-
pie - anti bond e-
sigma- anti bond e-

Question 10

what is beer lambert law

Answer 10

A=Ecl
e= molar absorption of analyte
c=concentration of analyte
l=path length

Question 11

factors which influence UV-VIS abs

Answer 11

• measure wavelength
• solvent
• pH of solution if analyte is acid/base
• temperature

Question 12

when a molecule looses an electron what does it make

Answer 12

unstable radical cation

Question 13

what is analysed for molecular weight

Answer 13

the unstable radical cation

Question 14

what is analysed In general

Answer 14

the cation

Question 15

mass spectra is a plot of each ….. vs the m/z ration

Answer 15

cation

Question 16

what is the base peak/ M peak

Answer 16

tallest peak

Question 17

what is the M+1 peak

Answer 17

last peak

Question 18

odd molecular ion have …. number of N2 atoms

Answer 18

odd

Question 19

in the alkyl halides the Ci have 2 common isotopes 35Ci and 37 Ci in the ratio of

Answer 19

3:1

Question 20

2 chloropropane is in a ratio of

Answer 20

3:1

Question 21

Bromine is in a ration of

Answer 21

1:1

Question 22

how do charged particles make a magnetic field

Answer 22

spin on axis

Question 23

how many energy states are there for a proton in a magnetic field

Answer 23

2

Question 24

what can you interpret from 1H NMR

Answer 24

no of signals
position of signals
intensity of signals
spin-spin splitting of signals

Question 25

a shielded nucleus have a ……… resultant field

Answer 25

smaller

Question 26

a shielded nucleus has a ………… magnetic field

Answer 26

larger

Question 27

as electron density around nucleus increases the resultant magnetic field has a ……… frequency

Answer 27

lower

Question 28

as electron density around nucleus increases the absorbance shifts ……..

Answer 28

upfield