from revision so far Flashcards
visible light wavelength range
400nm
700nm
what colour has a visible light wavelength of 400nm
blue
what colour has a visible light wavelength of 700nm
red
how do u turn nm into m
x 10^-9
/1000 then /1000 then /1000
units of wavelength
nm
cm
m
units for speed of light
nm s-1
cm s-1
m s-1
frequency, v units
s-1
frequency definition
number of wavelengths per second
energy of one photon in J
E=hv
units of h planks constant
Js
6.626x10^-34
what is spec the study of
light and matter
absorption spec
e- absorbing certain photons of light and transitioning to a higher energy level
emission spec
e- releasing specific photons of light and returning to ground level
stimulated emission spec
incident ray is applied onto an e- in order for it to release photons and transition to lower energy levels
incident ray energy = transition energy = energy of emission
wavelength
frequency
speed of light
c = v /\
energy of 1 photon
planks
frequency
E=hv
wavenumber
1/ /\
cm-1 m-1 nm-1
bc its 1/ wavelength units
E = hc wavenumber (1//)
energy in J
if a question relates ev into cm-1 what is it relating it to
wavenumber
bc its 1//\ units (cm, m etc)
u would use wavenumber as the energy
photoelectron spec
energy is used to remove an e- from an e- pair.
the energy can be found:
hv= IE + Ke
ionisation energy + kinetic energy
absorbance is
log(transmittance)
transmittance is
i / i0
% transmittance is
I / i0 x100
beer Lambert equation
A = E c l
a = abs
E = molar extinction coefficient (mol-1dm3 cm-1)
c= conc (moldm-3)
l = length of curvette (cm)
beer Lambert plotting A against c
gradient = E
small conc: signal intensity is too low and noise is higher
larger conc: molecules interact too much with eachother + affects absorbance
steps for wt%
find conc
conc = moles in 100cm3
conc x rmm = mass of drug in 1000cm3
find mass of drug in x cm3 (use ratio)
divide mass in x cm3 with the mass of sample (tablet etc)
