HEXANE - (110-54-3)

Introduction

Name: hexane; n-hexane
* IUPAC
CAS Number: 110-54-3
Chemical Formula: C6H14 or CH3(CH2)4CH3
Molar Mass: 86.17536 g
Mass Percent: C 83.625 %; H 16.374 % 
Isomers:  2-methylpentane  •  3-methylpentane

Classification

• organic • alkane

Uses/Function

• "By far the most important use of hexane is in solvents used for a variety of purposes, such as the extraction of oils from seeds and vegetables; as a degreaser and cleaning agent for printing equipment; as a solvent in glues such as rubber cement; as an ingredient in inks and varnishes; in the shoe and leather manufacturing industry; and in the roofing industry.
Hexane poses both safety and health risks for humans and other animals. The liquid vaporizes easily and the vapors formed ignite easily and may even explose under the proper conditions. The primary health hazard related to hexane occurs by breathing in the compound. When inhaled, it can cause numbness in the hands and feet, weakness in the feet and lower legs, paralysis of the arms and legs,, muscle wasting, damage to the nerves, nausea and vomiting, jaundice, skin rashes, irritation of the eyes and throat, blurred vision, mental confusion, and coma. There is no evidence however, that hexane is carcinogenic.
The health hazards posed by hexane are of concern in only two circumstances: among workers who handle the liquid on a regular basis; and among people who deliberately inhale the compound as part of a solvent for the purpose of getting 'high.' In both cases, a person is exposed to much higher concentrations of hexane that one would encounter in commercial or industrial products. The practice of glue-sniffing, which has become popular among some teenagersm can result in serious health problems, including dizziness, increased heart rate, high blood pressure, disorientation, confusion, and occasionally violent impulses or suicide attempts." 1

Physical Properties

Melting Point:*
-95.3°C 2 = 177.85 K = -139.54°F
Boiling Point:*
69°C 3 = 342.15 K = 156.2°F
68°C 4 = 341.15 K = 154.4°F

* - 1 atm pressure

Bonding

Double Bonds: 0
Triple Bonds: 0
Sigma Bonds: 19
Pi Bonds: 0
Total: 19
Carboxyl Groups: 0
Hydroxyl Groups: 0
Hybridization: each carbon is sp3
Bonding: polar covalent
Ionic Character: 10.61 %

Thermochemistry

ΔHf° (ℓ): -47.52 kcal/mol 5 = -198.82 kJ/mol
ΔHf° (g): -39.96 kcal/mol 5 = -167.19 kJ/mol
S° (ℓ): 70.76 cal/(mol•K) 6 = 296.06 J/(mol•K)
S° (g): 92.83 cal/(mol•K) 6 = 388.40 J/(mol•K)
ΔGf° (ℓ): -0.91 kcal/mol 7 = -3.81 kJ/mol
ΔGf° (g): -0.06 kcal/mol 7 = -0.25 kJ/mol
The heat of combustion is the amount of heat released when one mole of a substance undergoes combustion according to the general reaction equation:
CxHyOz + 0.25(4x+y-2z) O2 (g) → x CO2 (g) + 0.5y H2O (ℓ)

ΔHcomb° (ℓ): -994.985 kcal = -4163.04632 kJ
ΔHcomb° (g): -1002.545 kcal = -4194.67736 kJ

Reactions

Safety Information

NFPA 704 Ratings:
Health: 2 - Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury.
Flammability: 4 - Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Includes pyrophoric substances. Flash point below 23°C (73°F).
Reactivity: 0 - Normally stable, even under fire exposure conditions, and is not reactive with water.

For More Information

Sources

(1) - Schlager, Neil, Weisblatt, Jayne, Newton, David E., and Montney, Charles B. Chemical Compounds Vol. 2; Thomson-Gale: Detroit, MI, 2006; pp 354-5.
(2) - Lide, David R. CRC Handbook of Chemistry and Physics, 83rd ed.; CRC Press: Boca Raton, FL, 2002; p 3-186.
(3) - Estok, George K. Organic Chemistry: A Short Text; W.B. Saunders: Philadelphia, 1959; p 29.
(4) - Shriner, Ralph L., Fuson, Reynold C., and Curtin, David Y. The Systematic Identification of Organic Compounds, 4th ed.; John Wiley & Sons: New York, 1962; p 314.
(5) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:80.
(6) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:80.
(7) - Dean, John A. Lange's Handbook of Chemistry, 12th ed.; McGraw-Hill Book Company: New York, NY, 1979; p 9:80.