# Acetonitrile (data page)

This page provides supplementary chemical data on acetonitrile.

## Material Safety Data Sheet

The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet (MSDS) for this chemical from a reliable source and follow its directions.
* SIRI
* Fisher Scientific.

## Structure and properties

Structure and properties :
| Index of refraction, n$_D$ | 1.344 at 20.0 °C |
| Abbe number | ? |
| Dielectric constant, ε$_r$ | 36.64 ε$_0$ at 20 °C |
| Dipole Moment, | 3.84 D |
| Bond strength | ? |
| Bond length | ? |
| Bond angle | ? |
| Magnetic susceptibility | ? |
| Viscosity | 0.441 mPa·s at 0 °C 0.343 mPa·s at 25 °C |
| Surface tension | 29.29 dyn/cm |

## Thermodynamic properties

Phase behavior :
| Triple point | 229.32 K (−43.83 °C), 167 Pa |
| Critical point | 545 K (272 °C), 4.87 MPa |
| Std enthalpy change of fusion, Δ$_{fus}$H$^o$ | 8.167 kJ/mol (crystal I → liq) |
| Std entropy change of fusion, Δ$_{fus}$S$^o$ | 35.61 J/(mol·K) (crystal I → liq) |
| Std enthalpy change of vaporization, Δ$_{vap}$H$^o$ | 33.225 kJ/mol at 25 °C 29.75 at 81.6 °C (BP) |
| Std entropy change of vaporization, Δ$_{vap}$S$^o$ | 111.44 J/(mol·K) at 25 °C |
| Solid properties ||
| Std enthalpy change of formation, Δ$_f$H$^o$$_{solid}$ | ? kJ/mol at 25 °C |
| Standard molar entropy, S$^o$$_{solid}$ | ? J/(mol K) |
| Heat capacity, c$_p$ | 92.36 J/(mol K)at 298.15 K |
| Std enthalpy change of state transition, Δ$_{trs}$H$^o$ | 0.8979 kJ/mol at −56.2 °C (crystal II → crystal I) |
| Std entropy change of state transition, Δ$_{trs}$S$^o$ | 4.14 J/(mol·K) at −56.2 °C (crystal II → crystal I) |
| Liquid properties ||
| Std enthalpy change of formation, Δ$_f$H$^o$$_{liquid}$ | −40.56 kJ/mol |
| Standard molar entropy, S$^o$$_{liquid}$ | 149.62 J/(mol K) |
| Enthalpy of combustion, Δ$_c$H$^o$ | −1256.33 kJ/mol |
| Heat capacity, c$_p$ | 91.7 J/(mol K) at 25 °C |
| Gas properties ||
| Std enthalpy change of formation, Δ$_f$H$^o$$_{gas}$ | −74.04 kJ/mol |
| Standard molar entropy, S$^o$$_{gas}$ | ? J/(mol K) |
| Heat capacity, c$_p$ | ? J/(mol K) |

## Vapor pressure of liquid

| P in mm Hg | P in mm Hg | 1 | 10 | 40 | 100 | 400 | 760 |
| T in °C | T in °C | −47.0$_{(s)}$ | −16.3 | 7.7 | 27.0 | 62.5 | 81.8 |
Table data obtained from CRC Handbook of Chemistry and Physics, 44th ed. The "(s)" notation indicates temperature of solid/vapor equilibrium. Otherwise the data is temperature of liquid/vapor equilibrium.

## Distillation data

Vapor-liquid Equilibrium for Acetonitrile/Water P = 760 mmHg :
| BP Temp. °C | % by mole acetonitrile | % by mole acetonitrile |
| BP Temp. °C | liquid | vapor |
| 86.5 | 2.9 | 26.3 |
| 81.1 | 9.3 | 50.5 |
| 80.0 | 14.2 | 55.9 |
| 78.6 | 25.4 | 61.7 |
| 77.4 | 40.2 | 65.5 |
| 76.7 | 50.7 | 66.4 |
| 76.6 | 52.7 | 67.3 |
| 76.0 | 71.8 | 72.8 |
| 76.6 | 83.9 | 78.0 |
| 76.8 | 85.6 | 76.1 |
| 80.4 | 98.6 | 94.5 |
Vapor-liquid Equilibrium for Acetonitrile/Methanol P = 760 mmHg :
| BP Temp. °C | % by mole methanol | % by mole methanol |
| BP Temp. °C | liquid | vapor |
| 79.20 | 2.5 | 9.5 |
| 77.95 | 4.0 | 13.5 |
| 76.77 | 5.5 | 17.5 |
| 75.12 | 9.7 | 26.5 |
| 73.12 | 14.0 | 33.0 |
| 72.07 | 17.0 | 37.5 |
| 70.96 | 20.0 | 420 |
| 68.85 | 24.7 | 45.5 |
| 68.39 | 28.9 | 50.5 |
| 66.00 | 41.5 | 59.5 |
| 65.35 | 47.0 | 62.5 |
| 64.75 | 54.5 | 65.5 |
| 64.34 | 63.0 | 71.5 |
| 64.03 | 69.0 | 74.5 |
| 63.80 | 74.5 | 78.9 |
| 63.77 | 82.5 | 82.5 |
| 63.76 | 86.0 | 86.0 |
| 63.87 | 90.0 | 88.0 |
| 64.05 | 93.0 | 91.5 |
| 64.18 | 95.0 | 93.0 |
| 64.40 | 97.0 | 95.5 |
Vapor-liquid Equilibrium for Acetonitrile/Benzene P = 760 mmHg :
| BP Temp. °C | % by mole benzene | % by mole benzene |
| BP Temp. °C | liquid | vapor |
| 80.6 | 2.0 | 4.8 |
| 80.4 | 2.7 | 6.2 |
| 79.0 | 5.6 | 12.5 |
| 78.5 | 6.5 | 14.7 |
| 78.0 | 7.7 | 16.5 |
| 76.0 | 17.6 | 29.3 |
| 74.9 | 24.2 | 35.5 |
| 74.4 | 29.9 | 39.3 |
| 73.8 | 37.1 | 43.8 |
| 73.7 | 38.0 | 44.9 |
| 73.4 | 44.0 | 48.5 |
| 73.2 | 51.3 | 51.9 |
| 73.0 | 52.94 | 52.94 |
| 73.2 | 58.1 | 54.5 |
| 73.4 | 66.5 | 60.0 |
| 73.8 | 71.3 | 62.6 |
| 74.0 | 76.7 | 65.7 |
| 74.4 | 79.0 | 68.0 |
| 76.3 | 92.0 | 80.1 |
Vapor-liquid Equilibrium for Acetonitrile/Toluene P = 760 mmHg :
| BP Temp. °C | % by mole toluene | % by mole toluene |
| BP Temp. °C | liquid | vapor |
| 81.5 | 3.3 | 5.1 |
| 81.4 | 6.9 | 8.1 |
| 81.1 | 12.18 | 12.18 |
| 81.3 | 18.2 | 15.4 |
| 81.4 | 22.1 | 17.2 |
| 81.8 | 28.4 | 19.5 |
| 82.7 | 37.5 | 23.0 |
| 84.4 | 53.3 | 28.4 |
| 85.6 | 60.5 | 31.5 |
| 91.1 | 78.5 | 41.7 |
| 93.4 | 84.0 | 47.3 |
| 95.6 | 87.6 | 52.6 |
| 101.2 | 92.9 | 66.5 |
| 103.6 | 95.6 | 73.8 |
| 106.7 | 97.7 | 83.6 |
| 107.5 | 98.2 | 85.4 |

## Spectral data

UV-Vis :
| λ$_{max}$ | ? nm |
| Extinction coefficient, ε | ? |
| IR ||
| Major absorption bands | (liquid film) Wave numbertransmittance 3675 cm$^{−1}$79% 3544 cm$^{−1}$81% 3202 cm$^{−1}$77% 3164 cm$^{−1}$60% 3003 cm$^{−1}$52% 2944 cm$^{−1}$52% 2629 cm$^{−1}$81% 2410 cm$^{−1}$81% 2293 cm$^{−1}$44% 2254 cm$^{−1}$4% 1445 cm$^{−1}$30% 1378 cm$^{−1}$25% 1181 cm$^{−1}$84% 1040 cm$^{−1}$43% 918 cm$^{−1}$47% 750 cm$^{−1}$70% |
| NMR ||
| Proton NMR | |
| Carbon-13 NMR | |
| Other NMR data | |
| MS ||
| Masses of main fragments | |