Analytical Technique Flashcards
what is wavelength
distance between adjacent peaks of electric field
what is wave number directly proportional to
energy
formula for transmittance
T=1/I0 *100
formula for absorbance
A=-log (1/10)
bond stretching will increase if …….. is increases
amplitude
what are the principles of IR
- 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
what is quantum theory
molecules and atoms can only exist on certain energy levels
for a bond to absorb IR there must be a …… ………
dipole moment
energy states from lowest to highest
sigma - bond e- pie - bond e- pie- lone pair e- pie - anti bond e- sigma- anti bond e-
what is beer lambert law
A=Ecl
e= molar absorption of analyte
c=concentration of analyte
l=path length
factors which influence UV-VIS abs
- measure wavelength
- solvent
- pH of solution if analyte is acid/base
- temperature
when a molecule looses an electron what does it make
unstable radical cation
what is analysed for molecular weight
the unstable radical cation
what is analysed In general
the cation
mass spectra is a plot of each ….. vs the m/z ration
cation
what is the base peak/ M peak
tallest peak
what is the M+1 peak
last peak
odd molecular ion have …. number of N2 atoms
odd
in the alkyl halides the Ci have 2 common isotopes 35Ci and 37 Ci in the ratio of
3:1
2 chloropropane is in a ratio of
3:1
Bromine is in a ration of
1:1
how do charged particles make a magnetic field
spin on axis
how many energy states are there for a proton in a magnetic field
2
what can you interpret from 1H NMR
no of signals
position of signals
intensity of signals
spin-spin splitting of signals
a shielded nucleus have a ……… resultant field
smaller
a shielded nucleus has a ………… magnetic field
larger
as electron density around nucleus increases the resultant magnetic field has a ……… frequency
lower
as electron density around nucleus increases the absorbance shifts ……..
upfield
