0.5-lbm of a saturated vapor is converted to asaturated liquid by being cooled in aweighted piston-cylinderdevice maintained at 50 psia. During the phase conversion, thesystem volume decreases by 1.5 ft3; 250 Btu of heat areremoved; and the temperatureremains fixed at 15F. Estimatethe boiling point temperature of this substance when itspressure is 60 psia.