TABLE 18-1 Critical Temperatures and pressures Critical Temperature Critical Pressure Substance C K (atm) Water 374 647 218 cO2 31 304 72.8 Oxygen -118 155 50 Nitrogen-147 126 33.5 Hydrogen-239.9 33.3 12.8 Helium 267.9 5.3 2.3
Solid Critical point 218 目 Liquid 1.0 I Gas 0.006---1 Vapor Triple point 0.000.01 100374 T(°C) FIGURE 18-6 Phase diagram for water(note that the scales are not linear