1. The data I have for part 1
In this part of the lab, you measured the absorbance values of two solutions over a range of
wavelengths to determine the wavelength that is absorbed most by the dissolved solute. We call
this the wavelength of maximum absorbance. 1. Describe the solution concentrations and the
wavelengths of maximum absorption for both the copper(II) sulfate and the cobalt(II) chloride
solutions. Also record the absorbance value at the wavelength of maximum absorption. Solution
Concentration (M) Wavelengthx (nm) Absorbance IF CuSO CoCl 2. (a) Compare the color of
each solution to the color of the wavelength of light that is absorbed most effectively-shown by
the wavelength of maximum absorption. For each solution, how do the colors relate to one
another on a color wheel? Google "color wheel" if you don't happen to have one handy! (b)
Explain your answer to 2(a) in terms of "light absorbed" vs. "light reflected" by the solution.
Solution
1.For CuSO4 : . Conc.of solution = 0.060M
wavelength of max absorbance= 700nm
Absorbance value at wavelength of max. Absorbance= 0.52
For CoCl2 :. Conc. = 0.025M
Wavelength of maximum absorbance= 500nm
Absorbance at this wavelength= 0.23 .
2. (a) mThe light emitted by any substance (that we see) is the complementary light of that color
which it absorbs from visible light . As CuSO4 appears blue ,so it absorbs red light from the
visible light .And as CoCl2 appears of pink color so it absorbs Yellow color from incoming
wavelength of light .
Complementary colors are opposite to each others.

2. b) .As stated earlier , the light emitted(reflected) is of complementary color as light absorbed .As
in our case CuSO4 absorbs light of red colour and emit of blue colour while CoCl2 absorbs
yellow light and emits violet light .