4. [15] The Henry's law constant for ethanol in diethyl ether at 20C is 160 Torr. Find the activity and activity coefficient of ethanol in diethyl ether at 20C for a mole fraction of ethanol equal to 0.1 for the following two cases. The partial pressure of ethanol at this composition and temperature is 12.45 Torr, and the vapor pressure of pure ethanol at this temperature is 44.4 Torr. (1) Ethanol is thought as solvent. (2) Ethanol is thought as solute. 4. [15] The Henry's law constant for ethanol in diethyl ether at 20C is 160 Torr. Find the activity and activity coefficient of ethanol in diethyl ether at 20C for a mole fraction of ethanol equal to 0.1 for the following two cases. The partial pressure of ethanol at this composition and temperature is 12.45 Torr, and the vapor pressure of pure ethanol at this temperature is 44.4 Torr. (1) Ethanol is thought as solvent. (2) Ethanol is thought as solute