anayltical techiniques

  • Created by: anna888
  • Created on: 26-02-23 20:07
IR what is ir wavelenth
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IR what is frequency equation what is it meaured in
c/wavelength , hz
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IR what is on x axis, what is equation and why
wavenumber= 1/wavelength. bigger range and proportioanl to energy
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IR energy equation
energy= h x frequency
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IR whta is on y axis and what is equation
t %= I/I0 x 100
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IR desrvibe ir principals
when the frequency of the ir= the frequency of the bond stretching, ir energy is absorbed. this energy causes molecules to move from ground state to vibrational states producing a signal.
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IR why different signals for different moleules
different bonds have different stretching so different ir levels absorbed, different movement between ground and vibrational states
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IR consequnces of stronger bonds and smaller mass?what law is this
vibrate at higher frequency so absorb ir at higher wavenumbers- hookes law
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IR higher s character consequences
means have higher wavenumber.
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IR what is fingerprint region, general wavenumber
distinguising part between molecules, low wavenumber
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UV describe uv principals
signals represents the energy transition between bonding mo and antibonding mo.
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UV whats on axis
absorbance vs wavelength
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UV what law is used for absorbance calculations? whats the equation? when does law fail?
beer lambet. A= Ecl, fails at high concentrations
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UV factors effecting absorbance?
pH, temp, solvent, measurement wavelength
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MS describe mass spectroscopy principals (ei)
molecule vapourised by high energy elcetrons causing it to eject as electron. breaks molecule into fragments.
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MS phases of ms and types
gas, liquid, solid. gas= electron impact and chemcial ionisation
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MS what is base peak, moleular ion peak and m +1 peak
base peak= peak of greatest abundance. molecular ion peak= same rfm as molecule less one electron. M +1 peak= carbon 13 isotope presence
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MS whats on axis
m/e and relative abundance
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MS whats high resolution ms
takes fragment mass to 4 dp for more accurately distinguishing molecules of a similar rfm
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MS what is nitrogen rule
odd molecular ion number = odd number of nitrogens in molecule and vise versa
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NMR what is standard
tms- tetra methyl saline
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NMR describe principals
each spinning proton has its own magentic feild. in presense of another magentic feild , it either alligns with it or goes against it. if with=lower in energy. radiowaves cause protons to be excited to higher energy state. when radio waves stopped protons
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NMR peak individuality
each proton starts with individual enegry so decay is different
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NMR what does number of signals represent
number of hydrogens in chemically different envirnments
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NMR sheilded molecules chemical shift
sheilded= more e- density= feels less magnetic feild= absorbtion further upfeild= less frequency required for ressonance
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NMR desheilded molecules chemcial shift
electrongative molecules desheild= less e- density= feels more magentic field= absorbance occurs downfield= increases frequency required for ressonance
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NMR what does signal intesnity represent
height ratio of trace= ratio of no. of h in each envirnment
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NMR explain spin spin splitting patterns
singlet= no ajacent h's, feels only one magnetic field. doublet- 1 ajacent h, feels 2 magnetic feild triplet= 2 ajaent magnetic fields, feels 3 magnetic fields
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IR what is frequency equation what is it meaured in


c/wavelength , hz

Card 3


IR what is on x axis, what is equation and why


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Card 4


IR energy equation


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Card 5


IR whta is on y axis and what is equation


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