72. Solving a chemistry problem

2. When studying the attenuation of yellow light by iron hydroxide sols, the following data were obtained:
Sol concentration, % (wt.) 0.20 0.10 0.08
Layer thickness, mm 2.5 2.5 2.5
Share of transmitted light, % 1.7 11.8 18.6
Show the applicability of the Bouguer-Lambert-Beer equation for this disperse system. Calculate what proportion of light will be scattered by 0.75% sol with an absorbing layer thickness of 20 mm.