Alcohol (Ethanol) Chemical and Physical Properties

Chemical Properties of Ethanol

Chemical Formula

Ethanol’s chemical formula is C₂H₅OH.

Picture 1. Ethanol structural and molecular formula.
Ethanol, like all alcohols, has an OH (hydroxylic) group
attached to a saturated carbon atom.

Calories

1 gram of ethanol provides 7 Calories (kilocalories) of the “metabolizable energy” or 6.1 Calories of the “net metabolizable energy ^[7].”

Physical Properties of Ethanol

Appearance, Odor and Taste

At room temperature, ethanol is a clear, colorless, volatile liquid with a characteristic odor. When diluted, it is somewhat sweet, but concentrated alcohol has a strong, burning taste ^[1].

Solubility

Ethanol is highly soluble in water and organic solvents, but poorly soluble in fats and oils ^[1].

Density

Density of ethanol at 68 °F (20 °C) is 0.789 g/mL ^[1].

pH

Pure ethanol is neutral (pH ~7) ^[2]. Most alcoholic beverages are more or less acidic: table wine pH = 3.3-3.7 ^[3], beer pH ~ 4 ^[4].

Boiling Point

Boiling point of ethanol is 173.3 °F (78.5 °C) ^[1]

Melting Point

Melting point of ethanol is -173.4 °F (-114.1 °C) ^[1].

Freezing Point

• Wine (10% alcohol  by volume): 25 °F (-4 °C)
• Vodka (40% alcohol by volume): -10 °F (-23 °C)
• Pure alcohol (100% alcohol by volume): -175 °F (-115 °C) ^[5]

Flash Point

Flash point is the temperature at which ethanol is flammable – can catch fire:

• Beer (5% alcohol by weight) can catch fire, if ignited, at 144 °F (62 °C),
• Wine (10% alcohol by weight) at 120 °F (49 °C),
• Vodka (40% alcohol by weight) at 79 °F (26 °C) ^[5] and
• Concentrated alcohol (96% alcohol by weight) can catch fire at 63 °F (17 °C) ^[5].