Please help find the fraction adsorbed

Atrazine is an herbicide widely used for corn and is a common groundwater pollutant in the corn-producing regions of the United States. Use EPIWIN to find Koc for atrazine. Calculate the fraction of total atrazine that will be adsorbed to the soil given that the soil has an organic carbon content of 1.5%. The bulk density of the soil is 1.25g/cm3; this means that each cubic centimeter of soil (soil plus water) contains 1.25g of soil particles. The porosity of the soil is 0.4