# Cyclohexane (data page)

This page provides supplementary chemical data on cyclohexane.

## 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.
* Sigma Aldrich
* SIRI
* Science Stuff
* Fisher Scientific

## Structure and properties

Structure and properties :
| Index of refraction, n$_D$ | 1.4262 at 20 °C |
| Abbe number | ? |
| Dielectric constant, ε$_r$ | 2.023 ε$_0$ at 20 °C |
| Bond strength | ? |
| Bond length | 230 pm H–C |
| Bond angle | 109.5° H–C–H 109.5 °C–C–C 109.5° H–C–C |
| Magnetic susceptibility | ? |
| Surface tension | 27 dyn/cm at 10 °C 25.3 dyn/cm at 20 °C 15.7 dyn/cm at 80 °C |
| Viscosity | 1.03 mPa·s at 17 °C 0.93 mPa·s at 22 °C 0.86 mPa·s at 27 °C 0.75 mPa·s at 35 °C |

## Thermodynamic properties

Phase behavior :
| Triple point | 279.48 K (6.33 °C), 5.388 kPa |
| Critical point | 554 K (281 °C), 4070 kPa |
| Std enthalpy change of fusion, Δ$_{fus}$H$^o$ | 2.68 kJ/mol crystal I → liquid |
| Std entropy change of fusion, Δ$_{fus}$S$^o$ | 9.57 J/(mol·K) crystal I → liquid |
| Std enthalpy change of vaporization, Δ$_{vap}$H$^o$ | 32 kJ/mol |
| Std entropy change of vaporization, Δ$_{vap}$S$^o$ | 111.80 J/(mol·K) |
| Solid properties ||
| Std enthalpy change of formation, Δ$_f$H$^o$$_{solid}$ | ? kJ/mol |
| Standard molar entropy, S$^o$$_{solid}$ | ? J/(mol K) |
| Heat capacity, c$_p$ | ? J/(mol K) |
| Enthalpy of transition, Δ$_{trs}$H$^o$ | 6.7 kJ/mol at –87.0 °C crystal II → crystal I |
| Entropy of transition, Δ$_{trs}$S$^o$ | 36 J/(mol·K) at –87.0 °C crystal II → crystal I |
| Liquid properties ||
| Std enthalpy change of formation, Δ$_f$H$^o$$_{liquid}$ | –156.4 kJ/mol |
| Standard molar entropy, S$^o$$_{liquid}$ | 204 J/(mol K) |
| Enthalpy of combustion, Δ$_c$H$^o$ | –3919.6 kJ/mol |
| Heat capacity, c$_p$ | 156 J/(mol K) or 1.85 J/(g K) |
| Gas properties ||
| Std enthalpy change of formation, Δ$_f$H$^o$$_{gas}$ | –123.1 kJ/mol |
| Standard molar entropy, S$^o$$_{gas}$ | 298.19 J/(mol K) |
| Heat capacity, c$_p$ | 105.3 J/(mol K) |
| van der Waals' constants | a = 2311 L$^2$ kPa/mol$^2$ b = 0.1424 liter per mole |

## Vapor pressure of liquid

| P in mm Hg | P in mm Hg | 1 | 10 | 40 | 100 | 400 | 760 | 1520 | 3800 | 7600 | 15200 | 30400 | 45600 |
| T in °C | T in °C | –45.3$_{(s)}$ | –15.9$_{(s)}$ | 6.7 | 25.5 | 60.8 | 80.7 | 106.0 | 146.4 | 184.0 | 228.4 | — | — |
Table data obtained from CRC Handbook of Chemistry and Physics 44th ed. The "(s)" annotation indicates equilibrium temperature of vapor over solid. Otherwise value is equilibrium temperature of vapor over liquid.

## Distillation data

Vapor-liquid Equilibrium for Cyclohexane/Benzene P = 760 mm Hg :
| BP Temp. °C | % by mole benzene | % by mole benzene |
| BP Temp. °C | liquid | vapor |
| 79.5 | 10.1 | 13.1 |
| 78.9 | 17.1 | 21.1 |
| 78.4 | 25.6 | 29.3 |
| 77.8 | 34.3 | 37.6 |
| 77.5 | 42.8 | 44.5 |
| 77.4 | 52.5 | 52.9 |
| 77.4 | 57.1 | 56.4 |
| 77.6 | 66.5 | 64.5 |
| 77.9 | 75.9 | 72.8 |
| 78.2 | 81.0 | 77.7 |
| 78.6 | 86.3 | 83.4 |
| 79.3 | 94.5 | 92.6 |
Vapor-liquid Equilibrium for Cyclohexane/n-Hexane P = 101.0 kPa :
| BP Temp. °C | % by mole n-hexane | % by mole n-hexane |
| BP Temp. °C | liquid | vapor |
| 80.60 | 0.00 | 0.00 |
| 78.87 | 7.9 | 12.12 |
| 78.15 | 12.50 | 18.30 |
| 77.36 | 18.06 | 25.19 |
| 76.85 | 21.65 | 29.30 |
| 76.29 | 25.92 | 34.13 |
| 75.85 | 29.39 | 37.92 |
| 75.29 | 33.52 | 42.38 |
| 75.29 | 37.86 | 46.93 |
| 74.23 | 41.63 | 50.71 |
| 73.58 | 46.72 | 55.63 |
| 73.11 | 50.66 | 59.21 |
| 72.26 | 59.26 | 67.28 |
| 71.11 | 69.43 | 76.07 |
| 70.45 | 76.18 | 81.40 |
| 69.05 | 90.70 | 93.13 |
| 68.64 | 100.00 | 100.00 |
Vapor-liquid Equilibrium for Cyclohexane/Acetic acid P = 101.325 kPa :
| BP Temp. °C | % by mole acetic acid | % by mole acetic acid |
| BP Temp. °C | liquid | vapor |
| 79.60 | 2.75 | 6.31 |
| 79.32 | 5.20 | 9.85 |
| 78.84 | 101.2 | 15.01 |
| 78.53 | 14.06 | 18.04 |
| 78.50 | 21.39 | 21.98 |
| 78.81 | 35.30 | 26.20 |
| 79.13 | 49.30 | 29.00 |
| 79.33 | 56.10 | 30.00 |
| 81.44 | 74.60 | 33.50 |
| 81.66 | 75.80 | 34.20 |
| 85.18 | 86.70 | 40.00 |
| 90.52 | 92.50 | 49.20 |
| 91.90 | 93.20 | 51.70 |
| 95.52 | 94.57 | 57.82 |
| 98.94 | 95.96 | 63.33 |
| 105.75 | 97.84 | 75.69 |
| 113.16 | 99.33 | 90.67 |
Vapor-liquid Equilibrium for Cyclohexane/Ethanol P = 760 mm Hg :
| BP Temp. °C | % by mole ethanol | % by mole ethanol |
| BP Temp. °C | liquid | vapor |
| 73.99 | 2.0 | 17.5 |
| 69.08 | 3.0 | 30.2 |
| 66.94 | 6.5 | 35.8 |
| 66.08 | 8.1 | 36.3 |
| 66.37 | 8.6 | 36.5 |
| 65.59 | 12.5 | 38.8 |
| 65.23 | 15.1 | 39.6 |
| 65.12 | 20.6 | 40.8 |
| 64.93 | 25.8 | 41.5 |
| 64.87 | 28.3 | 41.8 |
| 64.84 | 31.5 | 42.6 |
| 64.78 | 36.6 | 43.0 |
| 64.77 | 40.3 | 43.1 |
| 64.77 | 43.1 | 43.1 |
| 64.78 | 44.4 | 43.8 |
| 64.81 | 50.0 | 44.3 |
| 64.88 | 55.7 | 45.5 |
| 65.01 | 61.3 | 46.0 |
| 64.99 | 62.1 | 45.8 |
| 65.25 | 67.8 | 47.5 |
| 65.56 | 73.8 | 50.5 |
| 66.03 | 76.3 | 49.6 |
| 65.93 | 77.6 | 51.5 |
| 66.40 | 78.1 | 49.8 |
| 66.90 | 80.9 | 54.5 |
| 67.26 | 83.3 | 57.8 |
| 67.98 | 85.3 | 59.5 |
| 68.86 | 88.1 | 62.3 |
| 69.44 | 89.8 | 65.3 |
| 70.11 | 90.9 | 67.8 |
| 71.42 | 92.9 | 72.5 |
| 72.48 | 95.1 | 77.8 |
Vapor-liquid Equilibrium for Cyclohexane/Isopropanol P = 760 mm Hg :
| BP Temp. °C | % by mole cyclohexane | % by mole cyclohexane |
| BP Temp. °C | liquid | vapor |
| 78.71 | 2.7 | 11.2 |
| 76.91 | 7.0 | 21.8 |
| 74.96 | 11.6 | 28.3 |
| 74.80 | 12.0 | 27.6 |
| 72.28 | 19.1 | 37.1 |
| 70.19 | 30.6 | 48.9 |
| 69.35 | 47.3 | 55.5 |
| 69.20 | 51.6 | 57.0 |
| 69.14 | 51.6 | 57.2 |
| 69.11 | 51.8 | 56.8 |
| 68.80 | 52.8 | 58.3 |
| 69.01 | 53.8 | 58.2 |
| 69.08 | 57.1 | 58.2 |
| 69.10 | 70.8 | 62.7 |
| 69.42 | 74.2 | 64.9 |
| 69.45 | 78.4 | 66.0 |
| 69.66 | 80.7 | 67.3 |
| 70.11 | 86.2 | 69.7 |
| 70.31 | 87.3 | 70.9 |
| 71.50 | 92.1 | 77.3 |
| 74.74 | 97.8 | 85.0 |
| 76.73 | 99.5 | 89.3 |

## Spectral data

UV-Vis :
| λ$_{max}$ | ? nm |
| Extinction coefficient, ε | ? |
| IR ||
| Major absorption bands | 1055–1000 cm$^{−1}$ |
| NMR ||
| Proton NMR | |
| Carbon-13 NMR | |
| Other NMR data | |
| MS ||
| Masses of main fragments | |