Diethyl Ether (C₄H₁₀O) — Properties, Uses & Safety

Overview

Diethyl ether (C4H10O), systematically named ethoxyethane, is a simple symmetrical ether with a molar mass of 74.12 g/mol. It is a colorless, highly volatile, and extremely flammable liquid with a characteristic sweet odor and a remarkably low boiling point of just 34.6 °C. The molecule consists of two ethyl groups connected by an oxygen atom (CH3CH2–O–CH2CH3), making it the most well-known member of the ether functional group class. Diethyl ether holds a special place in medical history as one of the first surgical anesthetics — its use in 1846 at Massachusetts General Hospital by William Morton marked the beginning of modern anesthesia and transformed surgery from a traumatic ordeal into a painless procedure. Although largely replaced by safer anesthetics today, diethyl ether remains one of the most important solvents in organic chemistry laboratories. Its low boiling point makes it easy to evaporate after liquid-liquid extractions, and its ability to dissolve a wide range of organic compounds while being only slightly miscible with water makes it ideal for separating organic products from aqueous mixtures. Diethyl ether can form dangerous peroxides upon prolonged exposure to air and light, which can explode when concentrated — a critical laboratory safety concern. GHS hazard codes include H224 (extremely flammable liquid and vapor), H302 (harmful if swallowed), and H336 (may cause drowsiness or dizziness). The flame and exclamation pictograms apply. For chemistry students, diethyl ether illustrates ether functional group chemistry, the concept of volatility and vapor pressure, liquid-liquid extraction techniques, the relationship between molecular structure and boiling point (ethers have lower boiling points than alcohols of similar mass due to the absence of hydrogen bonding as a donor), and the history of chemistry in medicine. It also provides important lessons about laboratory safety, including flammability, peroxide formation, and proper storage of volatile chemicals.

IUPAC Name

ethoxyethane

CAS Number

60-29-7

PubChem CID

3283

Molecular Formula

C₄H₁₀O

Molar Mass

74.123 g/mol

State at STP

liquid

Appearance

Colorless, volatile, highly flammable liquid