Determine the vapor pressure of a solution at 55°c that contains 34.2 g nacl in 375 ml of water. the vapor pressure of pure water at 55°c is 118.1 torr. the van't hoff factor for nacl is 1.9 determine the vapor pressure of a solution at 55°c that contains 34.2 g nacl in 375 ml of water. the vapor pressure of pure water at 55°c is 118.1 torr. the van't hoff factor for nacl is 1.9 115 torr 92.8 torr 108 torr 87.1 torr 112 torr