Problem 5. In an experiment to determine adsorption isotherm, 35 grams of arsenic-free soil sample and 1.5 L of water spiked with 27 mg/L arsenic were mixed in a bottle. The bottle was shaken for 24 hours on an auto-shaker for adsorption to reach equilibrium, after which a water sample was taken from the bottle and filtered. The arsenic concentration of the filtered water sample was determined to be 11 mg/L. Assuming adsorption follows linear adsorption isotherm model, find the distribution coefficient (Kn). (10 points)