Benzyl alcohol

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Benzyl alcohol
Benzyl alcohol sample and amber bottle.jpg
Benzyl alcohol sample and original bottle
Names
IUPAC name
Phenylmethanol
Other names
Benzenemethanol
Hydroxytoluene
Phenylcarbinol
Properties
C7H8O
C6H5CH2OH
Molar mass 108.14 g/mol
Appearance Colorless liquid
Odor Weak, slightly aromatic
Density 1.044 g/cm3
Melting point −15.2 °C (4.6 °F; 257.9 K)
Boiling point 205.3 °C (401.5 °F; 478.4 K)
3.50 g/100 ml (20 °C)
4.29 g/100 ml (25 °C)
Solubility Miscible in acetone, benzene, chloroform, diethyl ether, ethanol, methanol
Vapor pressure 0.18 kPa (60 °C)
Acidity (pKa) 15.40
Thermochemistry
217.8 J·mol-1K-1
-352 kJ/mol
Hazards
Safety data sheet Sigma-Aldrich
Flash point 93 °C (199 °F; 366 K)
Lethal dose or concentration (LD, LC):
1,250 mg/kg (rat, oral)
Related compounds
Related compounds
Phenol
Phenethyl alcohol
Diphenylmethanol
Triphenylmethanol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Benzyl alcohol or phenylmethanol is an aromatic alcohol with the formula C6H5CH2OH, commonly used in the production of various compounds and in the pharmaceutical industry.

The benzyl group is often abbreviated "Bn" (not to be confused with "Bz" which is used for benzoyl), thus benzyl alcohol is often denoted as BnOH.

Properties

Chemical

Benzyl alcohol can be oxidized to benzaldehyde and benzoic acid.

Reaction with concentrated haloacids yields benzyl halides. Reaction with hydrochloric acid, for example, gives benzyl chloride.

C6H5CH2OH + HCl → C6H5CH2Cl + H2O

Physical

Benzyl alcohol is a colorless liquid, almost odorless, slightly soluble in water.

Availability

Benzyl alcohol is sold by chemical suppliers. Can also be purchased online.

Benzyl alcohol can sometimes be found in hardware and art/painting stores as solvent, mostly pure, though most of the time mixed with other solvents.

Some window cleaning products and mouthwashers contain benzyl alcohol, albeit in a small percentage.

Preparation

Can be prepared by hydrolyzing benzyl chloride with sodium hydroxide.

C6H5CH2Cl + NaOH → C6H5CH2OH + NaCl

The benzyl chloride used for the reaction can be obtained by chlorinating toluene under UV light.

Projects

  • Make benzyl chloride
  • Make benzaldehyde
  • Make perfumes

Handling

Safety

Benzyl alcohol has low toxicity and has low volatility. It is however, severely toxic and highly irritating to the eye.

Storage

Benzyl alcohol should be kept in closed bottles, preferably in air-tight bottles, if you intend to store it for long periods of time.

Disposal

No special disposal is required.

References

Relevant Sciencemadness threads