# Benzene (data page)

## 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 such as SIRI, and follow its directions. MSDS for benzene available at AMOCO.

## Structure and properties

Structure and properties
Index of refraction, nD1.5011 at 20°C
Abbe number?
Dielectric constant, εr(2.274 – 0.0020ΔT) ε0
T = T – 25 °C)
Bond strength ?
Bond length1.39 Å C-C[1]
Bond angle120°C–C–C
120° H–C–C
Magnetic susceptibility ?
Surface tension28.88 dyn/cm at 25°C
Viscosity[2]
 0.7528 mPa·s at 10°C 0.6999 mPa·s at 15°C 0.6516 mPa·s at 20°C 0.6076 mPa·s at 25°C 0.5673 mPa·s at 35°C 0.4965 mPa·s at 40°C 0.4655 mPa·s at 45°C 0.4370 mPa·s at 50°C 0.4108 mPa·s at 55°C 0.3867 mPa·s at 60°C 0.3644 mPa·s at 65°C 0.3439 mPa·s at 70°C 0.3250 mPa·s at 75°C 0.3075 mPa·s at 80°C

## Thermodynamic properties

Phase behavior
Triple point278.5 K (5.4 °C), 4.83 kPa
Critical point562 K (289 °C), 4.89 MPa
Std enthalpy change
of fusion
, ΔfusHo
9.9 kJ/mol at 5.42 °C
Std entropy change
of fusion
, ΔfusSo
35.5 J/(mol·K) at 5.42 °C
Std enthalpy change
of vaporization
, ΔvapHo
33.9 kJ/mol at 25°C
30.77 kJ/mol at 80.1°C
Std entropy change
of vaporization
, ΔvapSo
113.6 J/(mol·K) at 25°C
87.1 J/(mol·K) at 80.1°C
Solid properties
Std enthalpy change
of formation
, ΔfHosolid
? kJ/mol
Standard molar entropy,
Sosolid
45.56 J/(mol K)
Heat capacity, cp118.4 J/(mol K) at 0°C
Liquid properties
Std enthalpy change
of formation
, ΔfHoliquid
+48.7 kJ/mol
Standard molar entropy,
Soliquid
173.26 J/(mol K)
Enthalpy of combustion, ΔcHo–3273 kJ/mol
Heat capacity,[2] cp134.8 J/(mol K)
Gas properties
Std enthalpy change
of formation
, ΔfHogas
+82.93 kJ/mol
Standard molar entropy,[3]
Sogas
269.01 J/(mol K)
Heat capacity,[2] cp82.44 J/(mol K) at 25°C
van der Waals' constants[4]a = 1823.9 L2 kPa/mol2
b = 0.1154 liter per mole

## Vapor pressure of liquid

 P in mm Hg 1 10 40 100 400 760 1520 3800 7600 15200 30400 45600 T in °C –36.7(s) –11.5(s) 7.6 26.1 60.6 80.1 103.8 142.5 178.8 221.5 272.3 —

Table data obtained from CRC Handbook of Chemistry and Physics 44th ed. Note: (s) notation indicates equilibrium temperature of vapor over solid, otherwise value is equilibrium temperature of vapor over liquid.

log of Benzene vapor pressure. Uses formula: $\scriptstyle \log_e P_{mmHg} =$$\scriptstyle \log_e (\frac {760} {101.325}) - 8.433613\log_e(T+273.15) - \frac {6281.040} {T+273.15} + 71.10718 + 6.198413 \times 10^{-06} (T+273.15)^2$ obtained from CHERIC[2] Note: yellow area is the region where the formula disagrees with tabulated data above.

## Distillation data

BP Temp. °C  % by mole ethanol liquid Vapor-liquid Equilibrium for Benzene/Ethanol[5]P = 760 mm Hg 70.8 8.6 26.5 69.8 11.2 28.2 69.6 12.0 30.8 69.1 15.8 33.5 68.5 20.0 36.8 67.7 30.8 41.0 67.7 44.2 44.6 68.1 60.4 50.5 69.6 77.0 59.0 70.4 81.5 62.8 70.9 84.1 66.5 72.7 89.8 74.4 73.8 92.4 78.2

BP Temp. °C  % by mole methanol liquid Vapor-liquid Equilibrium for Benzene/Methanol[5]P = 760 mm Hg 70.67 2.6 26.7 66.44 5.0 37.1 62.87 8.8 45.7 60.20 16.4 52.6 58.64 33.3 55.9 58.02 54.9 59.5 58.10 69.9 63.3 58.47 78.2 66.5 59.90 89.8 76.0 62.71 97.3 90.7

BP Temp. °C  % by mole benzene liquid Vapor-liquid Equilibrium for Benzene/Acetone[5]P = 101.325 kPa 57.34 11.7 7.4 57.48 12.8 8.1 57.75 15.1 9.5 59.21 26.7 16.6 59.24 27.0 16.7 60.01 32.7 20.2 60.71 37.3 23.1 61.05 39.8 24.7 61.91 45.0 27.9 62.82 50.2 31.7 63.39 53.4 33.9 63.79 55.4 35.3 64.22 57.2 37.0 64.99 61.3 39.9 67.88 73.0 51.2 70.21 80.7 60.1 72.23 86.1 67.9

BP Temp. °C  % by mole hexane liquid Vapor-liquid Equilibrium for Benzene/n-Hexane[5]P = 760 mmHg 77.6 7.3 14.0 75.1 17.2 26.8 73.4 26.8 37.6 72.0 37.2 46.0 70.9 46.2 54.0 70.0 58.5 64.4 69.4 69.2 72.5 69.1 79.2 80.7 69.0 82.8 83.8 68.9 88.3 88.8 68.8 94.7 95.0 68.8 96.2 96.4

## Spectral data

UV-Vis
Ionization potential9.24 eV (74525.6 cm−1)
S14.75 eV (38311.3 cm−1)
S26.05 eV (48796.5 cm−1)
λmax255 nm
Extinction coefficient, ε ?
IR
Major absorption bands[6]
Wave number transmittance (liquid film) 3091 cm−1 42% 3072 cm−1 49% 3036 cm−1 27% 1961 cm−1 77% 1815 cm−1 70% 1526 cm−1 81% 1479 cm−1 20% 1393 cm−1 84% 1176 cm−1 86% 1038 cm−1 49% 674 cm−1 4%
NMR
Proton NMR(CDCl3, 300 MHz) δ 7.34 (s, 6H)
Carbon-13 NMR(CDCl3, 25 MHz) δ 128.4
Other NMR data
MS
Masses of
main fragments

## Safety data

 Common synonyms None Physical properties Form: colorless liquid Stability: Stable, but very flammable Melting point: 5.5 C Water solubility: negligible Specific gravity: 0.87 Principal hazards *** Benzene is a carcinogen (cancer-causing agent). *** Very flammable. The pure material, and any solutions containing it, constitute a fire risk. Safe handling Benzene should NOT be used at all unless no safer alternatives are available. If benzene must be used in an experiment, it should be handled at all stages in a fume cupboard. Wear safety glasses and use protective gloves. Emergency Eye contact: Immediately flush the eye with plenty of water. Continue for at least ten minutes and call for immediate medical help. Skin contact: Wash off with soap and water. Remove any contaminated clothing. If the skin reddens or appears damaged, call for medical aid. If swallowed: Call for immediate medical help. Disposal It is dangerous to try to dispose of benzene by washing it down a sink, since it is toxic, will cause environmental damage and presents a fire risk. It is probable that trying to dispose of benzene in this way will also break local environmental rules. Instead, retain in a safe place in the laboratory (well away from any source of ignition) for disposal with other flammable, non-chlorinated solvents. Protective equipment Safety glasses. If gloves are worn, PVA, butyl rubber and viton are suitable materials.

## References

1. ^ Brown, LeMay, Bursten (2006). Chemistry: The Central Science. Upper Saddle River, NJ: Pearson Education. p. 1067. ISBN 0-13-109686-9.
2. ^ a b c d "Pure Component Properties" (Queriable database). Chemical Engineering Research Information Center. Retrieved 12 May 2007.
3. ^ "ETP Entropy of Benzene" (Queriable database). Dortmund Data Bank. Retrieved 7 Oct 2011.
4. ^ Lange's Handbook of Chemistry 10th ed, pp 1522-1524
5. ^ a b c d "Binary Vapor-Liquid Equilibrium Data" (Queriable database). Chemical Engineering Research Information Center. Retrieved 12 May 2007.
6. ^ "Spectral Database for Organic Compounds" (Queriable database). Advanced Industrial Science and Technology. Retrieved 10 June 2007.

Except where noted otherwise, data relate to standard ambient temperature and pressure.

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