Diethyl Ether Properties Preparation and Reactions

The organic compound diethyl ether is made up of two carbon atoms connected by an oxygen atom (C-O-C). It is a colourless, highly flammable, highly volatile liquid with an ethereal odour (sweet smelling). The molecular formula of diethyl ether is $C{{H}_{3}}C{{H}_{2}}OC{{H}_{2}}C{{H}_{3}}$ and the IUPAC name of diethyl ether is ethoxyethane.

Valerius Cordus synthesised diethyl ether in the year 1540 and gave it the name "sweet oil of vitriol" (oleum dulce vitrioli), reflecting the fact that it is produced by distilling a mixture of ethanol and sulfuric acid. August Sigmund Frobenius named the substance "ether" in 1729. It is frequently used as an engine starter fluid and as a solvent in laboratories. Before non-flammable medications like halothane were created, it was used as a general anaesthetic. Intoxicating recreational drugs have been made from it in the past.

Structure of Diethyl Ether

Diethyl ether usually referred to as ethyl ether, is an ether-class chemical molecule with the formula ${{({{C}_{2}}{{H}_{5}})}_{2}}O$. R-O-R. It is used to signify diethyl ether. Here, R stands for the alkyl group(${{C}_{2}}{{H}_{5}}$), and O stands for the oxygen atom.

Structure of Diethyl Ether

Physical Properties of Diethyl Ether

• Diethyl ether is a colourless liquid with a molar mass of 74.123 g/mol.

• It is highly volatile.

• It is highly flammable.

• It has a sweetish pungent odour.

• The boiling point is 34.6 °C (94.3 °F; 307.8 K).

• The melting point is -116.3 °C (-177.3 °F, 156.8 K).

• Its density is 0.7134 $\mathrm{g}/\mathrm{cm}^3$ , liquid.

• Its vapour pressure is 440 mmHg at 20 °C (58.66 kPa at 20 °C).

Chemical Properties of Diethyl Ether

• Combustion: Due to its high flammability, diethyl ether undergoes a combustion reaction to form carbon dioxide and water as products.

${{C}_{2}}{{H}_{5}}O{{C}_{2}}{{H}_{5}}\,+\,6{{O}_{2}}\,\to \,4C{{O}_{2\,}}+\,5{{H}_{2}}O$

• Halogenation: On halogenation with halogens like chlorine or bromine, diethyl ether undergoes a substitution reaction to form halo-substituted ether in the absence of sunlight.

${{C}_{2}}{{H}_{5}}O{{C}_{2}}{{H}_{5}}\,+\,C{{l}_{2}}\,\to \,{{C}_{2}}{{H}_{4}}(Cl)O{{C}_{2}}{{H}_{4}}(Cl)$

Preparation of Diethyl Ether

• Diethyl ether is produced by heating dry silver oxide with ethyl iodide.

• Williamson synthesis: This process involves heating sodium or potassium ethoxide with chloro, bromo, or iodo ethane. Diethyl ether and sodium iodide are the products of this reaction.

${{C}_{2}}{{H}_{5}}ONa\,+\,{{C}_{2}}{{H}_{5}}I\,\to \,{{C}_{2}}{{H}_{5}}O{{C}_{2}}{{H}_{5}}\,+\,NaI$

• Diethyl ether is produced by heating ethyl alcohol with alumina (Al2O3) at 250°C.

${{C}_{2}}{{H}_{5}}OH\,\xrightarrow[250]{A{{l}_{2}}{{O}_{3}}}\,{{C}_{2}}{{H}_{5}}O{{C}_{2}}{{H}_{5}}\,+\,{{H}_{2}}O$

• Laboratory method: A high concentration of ethyl alcohol is combined with a less concentrated sulfuric acid, and the resultant mixture is heated to roughly 140°C to produce diethyl ether.

${{C}_{2}}{{H}_{5}}OH\,+\,{{H}_{2}}S{{O}_{4}}\,+\,{{C}_{2}}{{H}_{5}}HS{{O}_{4}}\,+\,{{H}_{2}}O$

${{C}_{2}}{{H}_{5}}HS{{O}_{4}}\,+\,{{C}_{2}}{{H}_{5}}OH\,\to \,{{C}_{2}}{{H}_{5}}O{{C}_{2}}{{H}_{5}}\,+\,{{H}_{2}}S{{O}_{4}}$

Health Hazards of Diethyl Ether

• Highly flammable liquid and vapour and it may also form explosive peroxides.

• It is very harmful if swallowed and causes drowsiness, dizziness, and may induce vomiting.

• Continual exposure to ether could result in skin dryness or cracking and may also damage the proper functioning of kidneys.

Uses of Diethyl Ether

• It is used as a fuel:

Due to its high volatility and low flash point, diethyl ether, which has a high cetane number of 85–96, is utilised as a starting fluid in combination with petroleum distillates for gasoline and diesel engines.

• Chemistry:
  A typical aprotic solvent used in laboratories is diethyl ether.
  It dissolves in water at a rate of 1.5 g/100 g (1.0 g/100 ml) and has low solubility in water (6.05 g/100 ml at 25 °C). This makes it perfect for use as a non-polar solvent in liquid-liquid extraction, along with its high volatility.
  In addition to other reactions employing organometallic reagents, the Grignard reaction uses it as a typical solvent.

• Anesthesia:

Due to ether's better therapeutic index, or a bigger gap between an effective dose and a potentially toxic dose, diethyl ether generally replaced the use of chloroform as a general anesthetic.

• Recreational use:
  Ether is a recreational substance because of its anesthetic and euphoric properties. A long history of recreational use exists for the inhalant diethyl ether in anesthetic dosage.

Important Questions

1. Name a few physical properties of diethyl ether.

Ans: Diethyl ether is an organic compound that is colorless, ethereal odoured, highly flammable, and highly volatile liquid with a melting point and boiling point of -116.3 °C and 34.6 °C respectively.

2. Mention a method to prepare diethyl ether.

Ans: Diethyl ether can be prepared by distilling highly concentrated ethyl alcohol with sulphuric acid at about 140 degrees Celsius.

Summary

Ethyl ether, commonly referred to as diethyl ether, is a popular anesthetic that is a member of the large class of chemical compounds known as ethers. The molecular formula and the IUPAC name of diethyl ether are $C{{H}_{3}}C{{H}_{2}}OC{{H}_{2}}C{{H}_{3}}$ and ethoxyethane, respectively. It is a colourless, ethereal odoured, highly flammable, and highly volatile liquid with a melting point and boiling point of -116.3 °C and 34.6 °C, respectively. It is commonly used as a laboratory solvent, fuel, and anesthetic.

Practice Questions

1. Which one of these is not a synonym of diethyl ether?

1. Ethyl ether

2. Ethoxyethane

3. Ethoxymethane

4. Ether

2. Which of these is a structural isomer of diethyl ether?

1. Butanal

2. Butanol

3. Butane

4. Butene

Answers

1. (c)

2. (b)