Dumas Method
| Formula / Notation | M = (ρ × V × 22,400) / (mass of gas at STP) |
|---|---|
| Also Known As | Dumas bulb method, vapour density method, molar mass by vapour density |
What is Dumas Method?
A classical analytical technique for determining the nitrogen content of organic compounds. The sample is burned in excess oxygen, and the resulting nitrogen gas is measured volumetrically. The method was developed by Jean-Baptiste Dumas in the 19th century.
Formula & Notation
Other Names / Synonyms: Dumas bulb method, vapour density method, molar mass by vapour density
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
A classical analytical technique for determining the nitrogen content of organic compounds. The sample is burned in excess oxygen, and the resulting nitrogen gas is measured volumetrically. The method was developed by Jean-Baptiste Dumas in the 19th century.
The Dumas method was historically used to determine molar masses of organic compounds and gases (chloroform, ethanol, benzene vapour). Modern alternatives include mass spectrometry and osmometry, but Dumas's principle is still taught in undergraduate chemistry and is used for simple gas density meas…
The Dumas method requires heating glass bulbs to above the boiling point of the test liquid. Risk of glass bulb implosion or explosion if heated unevenly or if the substance has an unexpected vapour pressure. Use proper glass-handling precautions and protective screens if necessary.
The formula or notation for Dumas Method is: M = (ρ × V × 22,400) / (mass of gas at STP)