Water - Enthalpy and Entropy vs. Temperature
Figures and tables showing the enthalpy and entropy of liquid water as function of temperature - SI and Imperial Units.
Follow the links for definitions of the terms specific enthalpy and entropy .
The figures and tables below shows how water enthalpy and entropy changes with temperature (°C and °F) at water saturation pressure (which for practicle use, gives the same result as atmospheric pressure at temperatures < 100 °C (212 °F)).
See Water and Heavy Water - thermodynamic properties.
See also Water Boiling points at high pressure, Boiling points at vacuum pressure, Density, specific weight and thermal expansion coefficient, Dynamic and kinematic viscosity, Heat of vaporization, Ionization Constant, pKw , of normal and heavy water, Melting points at high pressure, Saturation pressure, Specific gravity, Specific heat (heat capacity) and Specific volume for online calculatores, and similar figures and tables as shown below.
Specific enthalpy and entropy for liquid water at saturation pressure at temperatures from 0 to 374 °C:
For full table with Entropy - rotate the screen!
| Temperature | Enthalpy, H | Entropy, S | |||||||
|---|---|---|---|---|---|---|---|---|---|
| (°C) | (kJ/kmol) | (kJ/kg) | (kWh/kg) | (kcal/kg) | (Btu(IT)/lb) | (kJ/(kmol K)) | (kJ/kgK) | (kWh/(kg K)) | (Btu(IT)/lbm *R) (kcal/(kg K)) |
| 0.01 | 0 | 0.000612 | 0.00000017 | 0.00015 | 0.00026 | 0.00000 | 0.00000 | 0.0000000 | 0.00000 |
| 10 | 757.1 | 42.021 | 0.01167 | 10.04 | 18.1 | 2.722 | 0.15109 | 0.0000420 | 0.03609 |
| 20 | 1511.8 | 83.914 | 0.02331 | 20.04 | 36.1 | 5.341 | 0.29648 | 0.0000824 | 0.07081 |
| 25 | 1888.6 | 104.83 | 0.02912 | 25.04 | 45.1 | 6.616 | 0.36722 | 0.000102 | 0.08771 |
| 30 | 2265.2 | 125.73 | 0.03493 | 30.03 | 54.1 | 7.868 | 0.43675 | 0.000121 | 0.10432 |
| 40 | 3018.2 | 167.53 | 0.04654 | 40.01 | 72.0 | 10.31 | 0.57240 | 0.000159 | 0.13672 |
| 50 | 3771.5 | 209.34 | 0.05815 | 50.00 | 90.0 | 12.68 | 0.70381 | 0.000196 | 0.16810 |
| 60 | 4525.3 | 251.18 | 0.06977 | 59.99 | 108.0 | 14.98 | 0.83129 | 0.000231 | 0.19855 |
| 70 | 5279.9 | 293.07 | 0.08141 | 70.00 | 126.0 | 17.21 | 0.95513 | 0.000265 | 0.22813 |
| 80 | 6035.5 | 335.01 | 0.09306 | 80.02 | 144.0 | 19.38 | 1.0756 | 0.000299 | 0.25690 |
| 90 | 6792.8 | 377.04 | 0.10473 | 90.05 | 162.1 | 21.49 | 1.1929 | 0.000331 | 0.28492 |
| 100 | 7551.8 | 419.17 | 0.11644 | 100.1 | 180.2 | 23.55 | 1.3072 | 0.000363 | 0.31222 |
| 110 | 8312.9 | 461.42 | 0.12817 | 110.2 | 198.4 | 25.56 | 1.4188 | 0.000394 | 0.33887 |
| 120 | 9076.6 | 503.81 | 0.13995 | 120.3 | 216.6 | 27.53 | 1.5279 | 0.000424 | 0.36493 |
| 140 | 10614 | 589.16 | 0.16366 | 140.7 | 253.3 | 31.33 | 1.7392 | 0.000483 | 0.41540 |
| 160 | 12169 | 675.47 | 0.18763 | 161.3 | 290.4 | 35.00 | 1.9426 | 0.000540 | 0.46398 |
| 180 | 13747 | 763.05 | 0.21196 | 182.3 | 328.1 | 38.54 | 2.1392 | 0.000594 | 0.51094 |
| 200 | 15354 | 852.27 | 0.23674 | 203.6 | 366.4 | 41.99 | 2.3305 | 0.000647 | 0.55663 |
| 220 | 17000 | 943.58 | 0.26211 | 225.4 | 405.7 | 45.36 | 2.5177 | 0.000699 | 0.60134 |
| 240 | 18693 | 1037.6 | 0.28822 | 247.8 | 446.1 | 48.68 | 2.7020 | 0.000751 | 0.64536 |
| 260 | 20448 | 1135.0 | 0.31528 | 271.1 | 488.0 | 51.97 | 2.8849 | 0.000801 | 0.68905 |
| 280 | 22284 | 1236.9 | 0.34359 | 295.4 | 531.8 | 55.28 | 3.0685 | 0.000852 | 0.73290 |
| 300 | 24232 | 1345.0 | 0.37361 | 321.2 | 578.2 | 58.65 | 3.2552 | 0.000904 | 0.77749 |
| 320 | 26343 | 1462.2 | 0.40617 | 349.2 | 628.6 | 62.14 | 3.4494 | 0.000958 | 0.82388 |
| 340 | 28727 | 1594.5 | 0.44292 | 380.8 | 685.5 | 65.94 | 3.6601 | 0.001017 | 0.87420 |
| 360 | 31739 | 1761.7 | 0.48937 | 420.8 | 757.4 | 70.56 | 3.9167 | 0.001088 | 0.93549 |
| 373.946 | 37551 | 2084.3 | 0.57898 | 497.8 | 896.1 | 79.40 | 4.4070 | 0.001224 | 1.05259 |
Specific enthalpy and entropy for liquid water at temperatures from 32 to 675 °F:
For full table with Entropy - rotate the screen!
| Temperature | Specific enthalpy, H | Specific entropy, S | |||||
|---|---|---|---|---|---|---|---|
| (°F) | (Btu(IT)/mol) | (Btu(IT)/lb) | (kJ/kg) | (kcal/kg) | (Btu(IT)/(kmol °R)) | (Btu(IT)/lb °R) (kcal/(kg K)) | (kJ/kgK) |
| 32.2 | 0.00 | 0.0003 | 0.0006 | 0.000 | 0.00 | 0.0000 | 0.0000 |
| 40 | 0.32 | 8.11 | 18.9 | 4.50 | 0.65 | 0.0163 | 0.0681 |
| 50 | 0.72 | 18.1 | 42.0 | 10.0 | 1.43 | 0.036 | 0.151 |
| 60 | 1.11 | 27.8 | 64.7 | 15.5 | 2.20 | 0.055 | 0.232 |
| 80 | 1.90 | 47.8 | 111 | 26.6 | 3.70 | 0.093 | 0.390 |
| 100 | 2.70 | 68.0 | 158 | 37.8 | 5.15 | 0.130 | 0.542 |
| 120 | 3.50 | 88.1 | 205 | 48.9 | 6.54 | 0.165 | 0.690 |
| 140 | 4.29 | 108 | 251 | 60.0 | 7.89 | 0.199 | 0.831 |
| 160 | 5.09 | 128 | 298 | 71.3 | 9.20 | 0.232 | 0.970 |
| 180 | 5.89 | 148 | 345 | 82.4 | 10.5 | 0.263 | 1.10 |
| 200 | 6.68 | 168 | 391 | 93.5 | 11.7 | 0.294 | 1.23 |
| 212 | 7.16 | 180 | 419 | 100 | 12.4 | 0.312 | 1.31 |
| 220 | 7.48 | 188 | 438 | 105 | 12.9 | 0.324 | 1.36 |
| 240 | 8.27 | 208 | 485 | 116 | 14.0 | 0.353 | 1.48 |
| 260 | 9.08 | 229 | 532 | 127 | 15.2 | 0.382 | 1.60 |
| 280 | 9.88 | 249 | 579 | 138 | 16.3 | 0.410 | 1.72 |
| 300 | 10.70 | 269 | 627 | 150 | 17.4 | 0.437 | 1.83 |
| 350 | 12.77 | 322 | 748 | 179 | 20.0 | 0.503 | 2.11 |
| 400 | 14.91 | 375 | 873 | 209 | 22.5 | 0.567 | 2.38 |
| 450 | 17.11 | 431 | 1002 | 239 | 25.0 | 0.630 | 2.64 |
| 500 | 19.38 | 488 | 1135 | 271 | 27.4 | 0.689 | 2.88 |
| 550 | 21.80 | 549 | 1277 | 305 | 30.0 | 0.754 | 3.16 |
| 600 | 24.49 | 617 | 1434 | 343 | 32.6 | 0.821 | 3.44 |
| 625 | 26.01 | 655 | 1523 | 364 | 34.1 | 0.858 | 3.59 |
| 650 | 27.70 | 698 | 1622 | 388 | 35.7 | 0.898 | 3.76 |
| 675 | 29.64 | 746 | 1736 | 415 | 37.5 | 0.944 | 3.95 |
Energy per unit mass (Specific energy - mass)
british thermal unit(international table)/pound (Btu(IT)/lb), gigajoule/tonne (GJ/t), kilocalorie/kilogram (kcal/kg) = calorie/gram(cal/g), kilojoule/kilogram (kJ/kg) = joule/gram (J/g), kilowatt hour/kilogram (kWh/kg)
- 1 Btu(IT)/lb = 0.002326 GJ/t = 2.326 kJ/kg = 0.5559 kcal/kg = 0.000646 kWh/kg
- 1 cal/g = 1 kcal/kg = 0.0041868 GJ/t = 4.1868 kJ/kg = 1.8 Btu(IT)/lb = 0.001162 kWh/kg
- 1 GJ/t = 1000 kJ/kg = 429.923 Btu(IT)/lb = 238.846 kcal/kg = 0.278 kWh/kg
- 1 J/g = 1 kJ/kg = 10-3 GJ/t = 0.23885 kcal/kg = 0.4299 Btu(IT)/lb = 0.0002778 kWh/kg
- 1 kcal/kg = 1 cal/g = 0.0041868 GJ/t = 4.1868 kJ/kg = 1.8 Btu(IT)/lb = 0.001162 kWh/kg
- 1 kJ/kg = 1 J/g = 10-3 GJ/t = 0.23885 kcal/kg = 0.4299 Btu(IT)/lb = 0.0002778 kWh/kg
- 1 kWh/kg = 1547.7 Btu(IT)/lb = 3.597 GJ/t = 3597.1 kJ/kg = 860.421 kcal/kg
Temperature
- T°C = (T°F - 32)/1.8
- T°C = TK - 273.15
- T°F = T°C *1.8 + 32
- T°F = (TK - 273.15) * 1.8 + 32
- TK = T°C + 273.15
- TK = T°R /1.8
- T°R = T°F + 459.67
- T°R = 1.8 K
Temperature difference:
- ΔT°C = ΔTK = 1.8*ΔT°F = 1.8*ΔT°R
- ΔT°F = ΔT°R = ΔT°C /1.8 = ΔTK /1.8
- ΔTK = ΔT°C = 1.8*ΔT°F = 1.8*ΔT°R
- ΔT°R = ΔT°F = ΔT°C /1.8 = ΔTK /1.8
