6. Oil reservoirs below ground frequently are in contact with underground water and, in connection with an oil drilling operation, you are asked to compute the solubility of water in a heavy oil at the underground conditions. These conditions are esti- mated to be 140°C and 410 bar. Experiments at 140°C and 1 bar indicate that the solubility of steam in the oil is x₁ = 35 × 10-4 (x1 mole fraction steam). Assume Henry's law in the form f₁ = H(T)x1, where H(T) is a constant, dependent only on the temperature, and f₁ is the fugacity of H2O. Also assume that the vapor pressure of the oil is negligible at 140°C. Data for H₂O are given in the steam tables.