Difference between revisions of "Diethyl ether"

Revision as of 20:36, 10 August 2015

Diethyl ether is an organic compound with the chemical formula (C₂H₅)₂O. It is a colorless liquid at room temperature and is most commonly used in the lab as a nonpolar solvent. It is one of the most common ethers.

Properties

Chemical

Diethyl ether is commonly used as an extraction solvent, though it is rather expensive for use as such. It is often used as a solvent in Grignard reactions, however it must be dried and distilled over elemental sodium immediately prior to use.

Physical

Diethyl ether is a colorless liquid which is less dense than water. It is slightly soluble in water, and will dissolve an even lower amount of water. Diethyl ether is extremely volatile and thus, due to its nervous system depression effects, large amounts should only be used outside or in a fume hood. The volatility of diethyl ether and its reputation for high flammability make it one of the riskier solvents to make use of.

Availability

Diethyl ether is fairly widely available from chemical suppliers, however it is usually very expensive. If reasonably pure but not reagent grade ether is acceptable, it can easily be distilled from many engine starter fluids found at automotive stores, gas stations, and department stores. It is often found alongside isomers of heptane, methylcyclohexane, and other hydrocarbons, but the very low boiling point of diethyl ether makes it easy to isolate.

Preparation

Diethyl ether is fairly easily prepared from concentrated sulfuric acid and azeotropic ethanol (though anhydrous works better), with the ether being distilled off. A way to remove water is necessary for driving the reaction to completion, as the continual generation of water as a byproduct slows the reaction down. Care must be taken in this preparation, however, due to diethyl ether's incredibly high flammibility and low flash point. Any distillation involving diethyl ether should not be walked away from. Boiling ether to dryness can cause explosions if sensitive peroxides are contained within, but this can be avoided by the addition of a small amount of higher-boiling solvent to the diethyl ether prior to distilling. such as mineral oil or glycerol. This additional solvent will be left behind post-distillation to solvate any peroxides and reduce their danger.

Projects

• Destruction of Styrofoam on contact
• Organic extractions

Handling

Safety

Diethyl ether is highly flammable and can easily be ignited by electrical devices such as light switches, or hot surfaces such as hot plates. Diethyl ether vapors are also denser than air, and thus pool on the ground where hot surfaces are more likely to be present. Diethyl ether is also a slight nervous system depressant, however it does not present a significant health risk. It has narcotic properties and has been known to cause temporary dependence, condition sometimes referred to as etheromania.

Storage

Diethyl ether is best stored in narrow neck reagent glass bottles. Diethyl ether will slowly form explosive peroxides in storage, though addition of a small amount of butylated hydroxytoluene (BHT) or storage over sodium hydroxide will prevent this. Care must be taken not to distill ether to dryness due to the trace amounts of peroxides formed over time. Iron or copper wire is known to inhibit the formation of peroxides.

Disposal

Diethyl ether can be safely burned, unless it has peroxides.

References

Relevant Sciencemadness threads

• Storage of Di-ethylether
• the dangers of diethyl ether