Phase behavior
Triple point 237.2 K (–35.9 °C), ? Pa
Critical point 561.6 K (288.5 °C), 5380 kPa
Std enthalpy change
of fusion
, ΔfusHo
8.8366 kJ/mol at –35.9 °C
Std entropy change
of fusion
, ΔfusSo
37.25 J/(mol·K) at –35.9 °C
Std enthalpy change
of vaporization
, ΔvapHo
33.91 kJ/mol at 20 °C
Std entropy change
of vaporization
, ΔvapSo
? J/(mol·K)
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
? kJ/mol
Standard molar entropy,
Sosolid
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
–169.7 kJ/mol
Standard molar entropy,
Soliquid
208.53 J/(mol K)
Enthalpy of combustion, ΔcHoliquid –1236.4 kJ/mol
Heat capacity, cp 129.0 J/(mol K)
Gas properties
Std enthalpy change
of formation
, ΔfHogas
–125.4 kJ/mol
Standard molar entropy,
Sogas
? J/(mol K)
Heat capacity, cp 77.5 J/(mol K) at 25 °C
Phase behavior
Triple point 133.39 K (-139.76 °C), ? Pa
Critical point 504 K (230 °C), 3.158 MPa
Std enthalpy change
of fusion
, ΔfusHo
? kJ/mol
Std entropy change
of fusion
, ΔfusSo
? J/(mol·K)
Std enthalpy change
of vaporization
, ΔvapHo
? kJ/mol
Std entropy change
of vaporization
, ΔvapSo
? J/(mol·K)
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
? kJ/mol
Standard molar entropy,
Sosolid
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
-74.2 kJ/mol
Standard molar entropy,
Soliquid
295.2 J/(mol K)
Heat capacity, cp 183.3 J/(mol K)
Gas properties
Std enthalpy change
of formation
, ΔfHogas
-43.5 kJ/mol
Standard molar entropy,
Sogas
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Phase behavior
Triple point 148.75 K (–124.4 °C), ? Pa
Critical point 536.9 K (263.8 °C), 5200 kPa
Std enthalpy change
of fusion
, ΔfusHo
5.37 kJ/mol
Std entropy change
of fusion
, ΔfusSo
36 J/(mol·K)
Std enthalpy change
of vaporization
, ΔvapHo
47.5 kJ/mol
Std entropy change
of vaporization
, ΔvapSo
126.6 J/(mol·K)
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
? kJ/mol
Standard molar entropy,
Sosolid
112.7 J/(mol K)
Heat capacity, cp 106.3 J/(mol K) at –124 °C
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
–303.0 kJ/mol
Standard molar entropy,
Soliquid
192.8 J/(mol K)
Enthalpy of combustion, ΔcHo –2021 kJ/mol
Heat capacity, cp 144.4 J/(mol K)
Gas properties
Std enthalpy change
of formation
, ΔfHogas
–255 kJ/mol
Standard molar entropy,
Sogas
322.49 J/(mol K)
Heat capacity, cp 85.56 J/(mol K) at 25°
van der Waals' constants[1] a = 1512 L2 kPa/mol2
b = 0.1029 liter per mole
Phase behavior
Triple point ? K (? °C), ? Pa
Critical point[2] 466 K (183 °C), 5570 kPa
Std enthalpy change
of fusion
, ΔfusHo
2.310 kJ/mol
Std entropy change
of fusion
, ΔfusSo
15.43 J/(mol·K)
Std enthalpy change
of vaporization
, ΔvapHo
26.12 kJ/mol
Std entropy change
of vaporization
, ΔvapSo
? J/(mol·K)
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
? kJ/mol
Standard molar entropy,
Sosolid
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
–196.4 kJ/mol
Standard molar entropy,
Soliquid
117.3 J/(mol K)
Enthalpy of combustion, ΔcHo –1167 kJ/mol
Heat capacity, cp 96.21 J/(mol K) at 0 °C
89.05 J/(mol K) at 25 °C
Gas properties
Std enthalpy change
of formation
, ΔfHogas
–170.7 kJ/mol
Standard molar entropy,
Sogas
250.3 J/(mol K)
Heat capacity, cp 55.32 J/(mol K) at 25 °C
Phase behavior
Triple point 289.8 K (16.7 °C), ? Pa
Critical point 593 K (320 °C), 57.8 bar
Eutectic point with water –26.7 °C
Std enthalpy change
of fusion
ΔfusHo
+11.7 kJ/mol
Std entropy change
of fusion
ΔfusSo
40.5 J/(mol·K)
Std enthalpy change
of vaporization
ΔvapHo
+23.7 kJ/mol
Std entropy change
of vaporization
ΔvapSo
? J/(mol·K)
Solid properties
Std enthalpy change
of formation
ΔfHosolid
? kJ/mol
Standard molar entropy
Sosolid
? J/(mol K)
Heat capacity cp ? J/(mol K)
Liquid properties
Std enthalpy change
of formation
ΔfHoliquid
−483.5 kJ/mol
Standard molar entropy
Soliquid
158.0 J/(mol K)
Enthalpy of combustion, ΔcHo –876.1 kJ/mol
Heat capacity cp 123.1 J/(mol K)
Gas properties
Std enthalpy change
of formation
ΔfHogas
–438.1 kJ/mol
Standard molar entropy
Sogas
282.84 J/(mol K)
Heat capacity cp 63.4 J/(mol K)
van der Waals' constants[3] a = 1782.3 L2 kPa/mol2
b = 0.1068 liter per mole
Phase behavior
Triple point 178.5 K (−94.3 °C), ? Pa
Critical point 508 K (235 °C), 48 bar
Std enthalpy change
of fusion
, ΔfusHo
+5.7 kJ/mol
Std entropy change
of fusion
, ΔfusSo
+32.3 J/(mol·K)
Std enthalpy change
of vaporization
, ΔvapHo
+31.3 kJ/mol
Std entropy change
of vaporization
, ΔvapSo
95 J/(mol·K)
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
? kJ/mol
Standard molar entropy,
Sosolid
? J/(mol K)
Heat capacity, cp [4] 96 J/(mol K)
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
−249.4 kJ/mol
Standard molar entropy,
Soliquid
200.4 J/(mol K)
Enthalpy of combustion, ΔcHo –1785.7 kJ/mol
Heat capacity, cp 125.5 J/(mol K)
Gas properties
Std enthalpy change
of formation
, ΔfHogas
−218.5 kJ/mol
Standard molar entropy,
Sogas
295.35 J/(mol K)
Heat capacity, cp 75 J/(mol K)
van der Waals' constants[3] a = 1409.4 L2 kPa/mol2
b = 0.0994 liter per mole
Phase behavior
Triple point[5] 229.32 K (−43.83 °C), 167 Pa
Critical point 545 K (272 °C), 4.87 MPa
Std enthalpy change
of fusion
, ΔfusHo
8.167 kJ/mol (crystal I → liq)
Std entropy change
of fusion
, ΔfusSo
35.61 J/(mol·K) (crystal I → liq)
Std enthalpy change
of vaporization
, ΔvapHo
33.225 kJ/mol at 25 °C
29.75 at 81.6 °C (BP)
Std entropy change
of vaporization
, ΔvapSo
111.44 J/(mol·K) at 25 °C
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
? kJ/mol at 25 °C
Standard molar entropy,
Sosolid
? J/(mol K)
Heat capacity, cp 92.36 J/(mol K)at 298.15 K
Std enthalpy change
of state transition
, ΔtrsHo
0.8979 kJ/mol at −56.2 °C
(crystal II → crystal I)
Std entropy change
of state transition
, ΔtrsSo
4.14 J/(mol·K) at −56.2 °C
(crystal II → crystal I)
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
−40.56 kJ/mol
Standard molar entropy,
Soliquid
149.62 J/(mol K)
Enthalpy of combustion, ΔcHo −1256.33 kJ/mol
Heat capacity, cp 91.7 J/(mol K) at 25 °C
Gas properties
Std enthalpy change
of formation
, ΔfHogas
−74.04 kJ/mol
Standard molar entropy,
Sogas
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Phase behavior
Triple point ? K (? °C), ? Pa
Critical point ? K (? °C), ? Pa
Std enthalpy change
of fusion
, ΔfusHo
? kJ/mol
Std entropy change
of fusion
, ΔfusSo
? J/(mol·K)
Std enthalpy change
of vaporization
, ΔvapHo
? kJ/mol
Std entropy change
of vaporization
, ΔvapSo
? J/(mol·K)
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
-1675.7 kJ/mol
Standard molar entropy,
Sosolid
50.92 J/(mol K)
Heat capacity, cp 89.7248 J/(mol K)
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
-1620.57 kJ/mol
Standard molar entropy,
Soliquid
67.24 J/(mol K)
Heat capacity, cp 192.5 J/(mol K)
Gas properties
Std enthalpy change
of formation
, ΔfHogas
? kJ/mol
Standard molar entropy,
Sogas
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Phase behavior
Triple point ? K (? °C), ? Pa
Critical point ? K (? °C), ? Pa
Std enthalpy change
of fusion
, ΔfusHo
? kJ/mol
Std entropy change
of fusion
, ΔfusSo
? J/(mol·K)
Std enthalpy change
of vaporization
, ΔvapHo
? kJ/mol
Std entropy change
of vaporization
, ΔvapSo
? J/(mol·K)
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
-3440 kJ/mol
Standard molar entropy,
Sosolid
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
? kJ/mol
Standard molar entropy,
Soliquid
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Gas properties
Std enthalpy change
of formation
, ΔfHogas
? kJ/mol
Standard molar entropy,
Sogas
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Phase diagram and crystalline states of ammonia
I. cubic, II. hcp, III. fcc, IV. orthorhombic
Phase behavior
Triple point 195.4 K (−77.75 °C), 6.060 kPa
Critical point 405.5 K (132.3 °C), 11.300 MPa
Std enthalpy change
of fusion
, ΔfusHo
+5.653 kJ/mol
Std entropy change
of fusion
, ΔfusSo
+28.93 J/(mol·K)
Std enthalpy change
of vaporization
, ΔvapHo
+23.35 kJ/mol at BP of −33.4 °C
Std entropy change
of vaporization
, ΔvapSo
+97.41 J/(mol·K) at BP of −33.4 °C
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
? kJ/mol
Standard molar entropy,
Sosolid
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
? kJ/mol
Standard molar entropy,
Soliquid
? J/(mol K)
Heat capacity, cp 80.80 J/(mol K)
Gas properties
Std enthalpy change
of formation
, ΔfHogas
−45.92 kJ/mol
Std Gibbs free energy change
of formation, ΔfGogas
−16.6 kJ/mol
Standard molar entropy,
Sogas
192.77 J/(mol K)
Heat capacity, cp 35.06 J/(mol K)
Heat capacity ratio, γ
at 15 °C
1.310
van der Waals' constants a = 422.5 l2 kPa/mol2
b = 0.03707 l/mol
Phase behavior
Triple point 267.13 K (–6.02 °C), ? Pa
Critical point 698.8 K (425.7 °C), 4890 kPa
Std enthalpy change
of fusion
, ΔfusHo
10.54 kJ/mol
Std entropy change
of fusion
, ΔfusSo
39.57 J/(mol·K) at –6.3 °C
Std enthalpy change
of vaporization
, ΔvapHo
55.83 kJ/mol at 25 °C
42.44 kJ/mol at 184.1 °C
Std entropy change
of vaporization
, ΔvapSo
? J/(mol·K)
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
? kJ/mol
Standard molar entropy,
Sosolid
? J/(mol K)
Heat capacity, cp ? J/(mol K)
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
31 kJ/mol
Standard molar entropy,
Soliquid
191. J/(mol K)
Enthalpy of combustion, ΔcHoliquid –3393 kJ/mol
Heat capacity, cp 193.7 J/(mol K) at 25 °C
Gas properties
Std enthalpy change
of formation
, ΔfHogas
87 kJ/mol
Standard molar entropy,
Sogas
? J/(mol K)
Heat capacity,[2] cp 148.7 J/(mol K) at 25 °C
van der Waals' constants[3] a = 2685 L2 kPa/mol2
b = 0.1369 liter per mole
  1. ^ CRC Handbook of Chemistry and Physics 47th ed, p D-104
  2. ^ a b "Pure Component Properties". Chemical Engineering Research Information Center. Archived from the original on 3 June 2007. Retrieved 27 May 2007. Cite error: The named reference "cheric_p" was defined multiple times with different content (see the help page).
  3. ^ a b c Lange's Handbook of Chemistry 10th ed, pp 1522-1524 Cite error: The named reference "lange1522" was defined multiple times with different content (see the help page).
  4. ^ Maass, O.; Walbauer, L.J., The specific heats and latent heats of fusion of ice and of several organic compounds, J. Am. Chem. Soc., 1925, 47, 1-9.
  5. ^ Vapor Pressures of Acetonitrile Determined by Comparative Ebulliometry, Michael B. Ewing* and Jesus C. Sanchez Ochoa, Journal of Chemical & Engineering Data 2004 49 (3), 486-491