This lecture covers the distribution of organics in multiphase systems, including scenarios with three phases present. It explains the fractions of a substance in each phase at equilibrium, using examples like air, water, and octanol. The exercises demonstrate the removal of air contaminants by rain, the estimation of Koc from Kow, and the contaminant retardation in groundwater. Additionally, it presents a 3-phase problem involving a soup bowl with a fat bubble and naphtalene, illustrating the estimation of ingested naphtalene amount.