Wavelength (nm) Absorbance 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390
Wavelength (nm) Absorbance 400 410 420 430 440 450 460 470 480 490 500 510 520 530 540 550
6
Wavelength (nm) Absorbance 560 570 580 590 600 610 620 630 640 650 660 670 680 690 700
Examine your plot carefully and decide the wavelength at which maximum absorbance occurs (the peak of absorption).
Once you have identified the region where the absorbance is high, you should then record absorbance at smaller intervals (say every 5nm) in order to obtain a more accurate determination of the wavelength at which maximal absorbance occurs (Xmax).
Do this for only a restriction range of wavelengths around the peak absorbance value — do not examine the entire range of wavelengths again ! Plot the spectrum with absorbance on the y-axis (dependent variable) and wavelength in nm on the x-axis (independent variable) and determine Xmax.
Using the value of wavelength where you get maximum absorption (Xmax), measure the absorption of all the other reaction tube samples (transfer to separate cuvettes) — ie reactions from tubes 2,3,4 and 5.
Complete the table below, entering data for all reaction samples