Using this mass ratio, what would be the concentration (in ppm) of PFOA in the pond water?

Problems 1. What is the mass of water in the pond, in kg? 2. What is the mass of sediment in the pond, in kg? 3. What is the mass of PFOA that spilled into the pond in kg? 4. Assuming that fraction of organic carbon is 30% by mass, solve for the mass ratio of PFOA in the sediment and water. In this case, the mass ratio is defined as:
. kg mass of the total PFOA that sorbs to the sediment mass ratio = kg of mass of the total PFOA that dissoves in the water
5. Using this mass ratio, what would be the concentration (in mg/kg) of PFOA in the sediments?
6. Using this mass ratio, what would be the concentration (in ppm) of PFOA in the pond water?
7. How would the concentration of C8 in the pond water change if the sediment had a lower organic carbon content? Please explain your answer.