Sorbic acid
| Names | |
|---|---|
| IUPAC name
(2E,4E)-hexa-2,4-dienoic acid
| |
| Other names
2E,4E-Hexadienoic acid
| |
| Properties | |
| C6H8O2 CH3(CH)4COOH | |
| Molar mass | 112.128 g/mol |
| Appearance | White solid |
| Odor | Faint fruity odor |
| Density | 1.204 g/cm3 (20 °C) |
| Melting point | 135 °C (275 °F; 408 K) |
| Boiling point | 228 °C (442 °F; 501 K) |
| 0.156 g/100 ml (20 °C) 0.191 g/100 ml (30 °C) | |
| Solubility | Soluble in glacial acetic acid, acetone, dioxane, ethanol, methanol Slightly soluble in diethyl ether, isopropanol, methyl acetate, propylene glycol Sparingly soluble in benzene, CCl4, cyclohexane, diisopropyl ether, glycerol, toluene, xylene |
| Vapor pressure | 0.01 mmHg at 20 °C |
| Acidity (pKa) | 4.76 |
| Thermochemistry | |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | 127 °C (260.6 °F; 400 K) |
| Related compounds | |
| Related compounds
|
Potassium sorbate |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Sorbic acid, or 2,4-hexadienoic acid, is a natural occurring organic chemical compound, with the formula CH3(CH)4CO2H
Contents
Properties
Chemical
With a pKa of 4.76, sorbic acid is about as acidic as acetic acid.
Physical
Sorbic acid is a colorless solid that is slightly soluble in water and sublimes readily.
Availability
Sorbic acid is sold as its salt form, potassium sorbate. Can also be bought online.
It can be isolated from the unripe berries of the Sorbus aucuparia (rowan tree), hence its name. Distillation of rowanberry oil affords parasorbic acid, the lactone of sorbic acid, which he converted to sorbic acid by hydrolysis.
Preparation
Sorbic acid can be easily made by acidifying potassium sorbate using a strong acid.
Lab methods involve condensation of malonic acid and trans-butenal, or crotonaldehyde and ketene.
Projects
- Food preservative
- Make sorbates (calcium sorbate, potassium sorbate, sodium sorbate)
- Additive for cold rubber
Handling
Safety
Sorbic acid has low toxicity, though may be irritant.
Storage
In closed plastic bottles.
Disposal
No special disposal is required. Discard it as you wish.
