[rob]

hello,

I know that the extinction coefficient of a sub. can be found by the slope of the straight line graph when plotting the concentration against absorbance in nm of a certain wavelength. For doing this I'm going to use experimental data and I'm not sure if the value i'll end up with, is the correct one. Therefore I want to know if there is somewhere I can find extinction coefficients for different sub at certain concentrations and absorbancies but this seems to be very unlikely and instead want to know how can I calculate it by ANY OTHER method besides the one I'm using.
What will the units of the coefficient be? Can anyone give an approximate idea how much should be the ex. coeff. of I2 0.004M when the absorbance @ 500nm is 0.413.
please help me

[Albert]

What will the units of the coefficient be? Can anyone give an approximate idea how much should be the ex. coeff. of I2 (iodine) 0.004M when the absorbance @ 500nm is 0.413.
please help me

e = A/l*c = 0.413/ 1 cm * 0.004 M = 103.25 L mol^-1 cm^-1 (or 103.25 * 1000 cm^2 mol^-1)