does UV/visible spectrum require a sample
yes
what does a UV spectrum show
broad bands rather than sharp lines
what happens in rotational molecular absorption spectra
dipoles rotate absorbing energy
what happens in vibrational molecular absorption spectra
bonds absorb energy and vibrate
what happens in electronic molecular absorption spectra
molecule changes electron configuration
what do most molecules do at room temp
have vibrational and electronic states
what happens when polychromatic light interacts with molecules of a compound
some of the molecules will absorb the radiation
what happens when certain types of electrons are excited to a higher energy state
there is an increase in the energy levels of rotational and vibrational states
what is beers law
the intensity of a beam of parallel monochromatic light decreases exponentially with the number of absorbed molecules
what does light scattering cause
absorbance>true
where do errors with light scattering increase
at shorter wavelengths
does IR have more or less energy than UV/visible light
less
what does absorption of IR transition in
what must absorption of IR cause
a change in the dipole moment of the molecule
what is polymorphism
the ability of a compound the adopt more than one three dimensional structure
what can IR spectroscopy identify
intramolecular bond stretches via change in dipole
what can HPLC methods be used for
to identify multiple components in systems as well as structurally similar ones
what can X-ray diffraction techniques identify
molecular structure