Question

18-10. Color and absorption spectra. Color Plate 17 shows coalored solutions and their spectra. From Table 18-1, predict the color of each solution from the wavelength of maximum absorption. Do observed colors agree with predicted colors?

Short answer

In Compound B and F the observed colors does not agree with the predicted colors. In Compound A,C,D and E the observed colors agree with the predicted colors.

Step-by-step solution

Definition

Spectrophotometry is a standard and inexpensive technique to measure light absorption or the amount of chemicals in a solution. It uses a light beam which passes through the sample, and each compound in the solution absorbs or transmits light over a certain wavelength.

Absorbance and the observed color in all compounds

The compound A has maximum absorbance at 760 nm. The predicted color from table 18-1 is green, and the observed color is green.

The compound B has maximum absorbance at 700 nm. The predicted color from table 18-1 is green, and the observed color is blue- green.

The compound C has maximum absorbance at 600 nm. The predicted color from table 18-1 is blue, and the observed color is blue.

The compound D has maximum absorbance at 530 nm. The predicted color from table 18-1 is violet, and the observed color is violet.

The compound E has maximum absorbance at 500 nm. The predicted color from table 18-1 is red or purple red, and the observed color is red.

The compound F has maximum absorbance at 410 nm. The predicted color from table 18-1 is green-yellow, and the observed color is yellow.