Difference between revisions of "Ethyl acetate"

Revision as of 04:07, 14 June 2015

Ethyl acetate or ethyl ethanoate is the organic compound with the chemical formula CH3-COO-CH2-CH3. The acetate ester of ethanol, ethyl acetate is a safe and common laboratory and domestic solvent with a pleasant odor.

Properties

Chemical

Ethyl acetate, like many other carboxylate esters, is prone to hydrolysis accelerated by basic conditions. Because ethyl acetate is cheap and easy to come by in some locations, it is sometimes intentionally hydrolyzed using sodium hydroxide into its component species: acetic acid and ethanol. The acetic acid produced reacts with the sodium hydroxide to form sodium acetate, effectively providing two useful and easily separable reagents.

Physical

Ethyl acetate is a clear, colorless, free-flowing liquid at room temperature. Ethyl acetate boils at 77.1 °C (170.8 °F) and has a density of about 0.897g/cm³, allowing it to float on water. It is moderately soluble (8.3g/100mL at 20 °C) in water and is soluble in or miscible with most organic solvents, including ethanol, acetone, and diethyl ether. As with other carboxylate esters, ethyl acetate has an ethereal, fruity smell. Ethyl acetate's chief use as a solvent comes from its ability to dissolve many water-insoluble substances, such as glues and lacquers, and it is often used as a substitute for another popular solvent in hardware stores, methyl ethyl ketone.

Availability

Ethyl acetate can often be found in hardware stores either in pure form as a solvent(sometimes labelled as MEK substitute) or as a component of mixed solvents, which may or may not allow its extraction via fractional distillation. Many acetone-free nail polish removers often contain it as well.

Preparation

Ethyl acetate is most often prepared by the Fischer esterification between ethanol and glacial acetic acid. Using anhydrous reagents and sulfuric acid as a catalyst and drying agent results in a roughly 65% yield. As with most such syntheses, this esterification is conducted under reflux and is benefited by the removal of water by some means, such as excess sulfuric acid or a desiccant. The ethyl acetate formed is difficult to remove from any remaining ethanol, though one way to do so is by dumping the products of the reaction into water, in which ethyl acetate is not highly soluble, forming a layer on top which can be separated off physically. The crude ethyl acetate is then washed with sodium bicarbonate solution to remove residual acids and gently distilled over a desiccant such as calcium chloride.

Projects

• Caffeine extraction
• Ethyl acetoacetate synthesis

Handling

Safety

Ethyl acetate is flammable as well as being a mild skin irritant, but is relatively nontoxic to humans.

Storage

Ethyl acetate can be stored relatively indefinitely, but may degrade over time in the presence of substantial water.

Disposal

Ethyl acetate does not have any special requirements for disposal, but it may be a better idea to recover it via distillation or hydrolyze it to useful ethanol and acetic acid instead.

References

Relevant Sciencemadness threads