Problem 4. A soil sample was extracted with dilute HCI and the extract was analyzed to determine the copper concentration of the soil sample prior to an adsorption experiment. This concentration was found to be 0.5 mg Cu per gram of soil. In an experiment to determine adsorption isotherm, 25 grams of this soil sample and 0.6 L of water spiked with 9 mg/L copper were mixed in a bottle. The bottle was shaken for 24 hours on an auto-shaker for adsorption to reach equilibrium. A water sample was then taken from the bottle and filtered, and the copper concentration of the filtered water sample was determined to be 6 mg/L. (1) Find the total copper mass in the bottle during the shaking. (10 points) (2) Find the adsorbed copper concentration (2.) of the soil after 24 hours of shaking. Report the q. value in the unit of mg/g. (10 points)