Critical behavior of dilute NaCl in H2O

The compositions of the saturated vapor and liquid phases are measured for the system NaCl-H₂O at 380°C, which is close to the critical point of pure water. The shape of the phase equilibrium curve is classical, which confirms a conclusion reached earlier on the basis of less accurate data. This implies that the long-range forces introduced by the NaCl suppress the non-classical effects present in pure H₂O. An empirical equation of a classical type fits these data.