A Nod to Tradition
October 8, 2009 § Leave a comment
This afternoon, my twelve General Chemistry Lab students and I will go through the motions of that famous ritual, learning to use the bunsen burner. It is a task required of every chemist, usually during their freshman year of studies. But why? In nearly six years of research, I have never used a bunsen burner for work and do not know anyone who has ever used a bunsen burner for work. The burner is rather unreliable, and not as safe as the hot plates commonly seen in research laboratories.
The answer: Bunsen burners are a tradition.
For fun, I looked up the history of the bunsen burner. Until the 19th century, heating things in the lab was a major problem. Furnaces and open flames were fine for some experiments, but when slower, even heating was needed chemists were at a loss. Frustrated scientists struggled with oil-based heaters and spirit lamps, which worked well for a few minutes before they deposited a greasy, sooty layer on the outside of the flask being heated, which reduced the amount of heat actually getting to the reaction mixture inside.
In the early 1800s, Humphry Davy and Michael Faraday ran a series of research experiments in which they discovered that the temperature of a flame is not a property of the gas itself, but rather of the rate of combustion of the gas. Combustion requires that a chemical compound be oxidized (an electron is removed) by an oxidizer such as oxygen. Oxygen is, of course, one of the major components of the air we breathe. Thus, Davy and Faraday hypothesized, if you increase the flow of air into a flame, you increase the rate of combustion and the heat of the flame. Later, during the course of his own research, Faraday developed a crude version of what we now know as the bunsen burner, with the twisting piece on the top to vary the intake of air. Unfortunately for Faraday (but fortunately for Bunsen) the new gas-air lamp did not catch on.
Robert Bunsen, a professor at Heidelberg, assigned one of his assistants to build him a burner in 1853 which would later be known as the “Bunsen burner”. It was an instant success for its even heating and controllable flame temperature.
Today we continue to pay tribute to Bunsen and those who came before him by learning to use the Bunsen burner, even though we may never come in contact with it again. Try to remember all the hard work that went into developing the burner – a semi-reliable heat source – as you struggle with the valve to get that little blue flame to appear.