issues and experts

SFU scientists develop new—and safer—flame test demonstration

September 11, 2019
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CONTACT:

John Canal and Dev Sharma, senior lecturers, Department of Chemistry, jcanal@sfu.ca, 778.782.7661; rsharma@sfu.ca, 778.782.4565;

Hamel Tailor, manager, lab operations, Department of Chemistry, 778.782.3350, lab_manager@sfu.ca

Shradhha Sharma, University Communications and Marketing, 778.782.3210, shradhha_sharma@sfu.ca

 

Remember chem lab? The popular ‘flame’ demonstration that educators use to show a variety of chemical phenomena is now safer for classrooms, thanks to Simon Fraser University chemists John Canal, Dev Sharma and Hamel Tailor.

The demonstration, also known as the rainbow demonstration or the rainbow flame test, has been a standard teaching tool at universities and high schools for decades. But its safety record is concerning: 32 documented accidents over a 19-year period. The SFU scientists say their method would have prevented an injury of the kind that recently resulted in a $60 million injury settlement in the United States.

Canal, who has been examining and redeveloping teaching tools for several years, became

convinced that the demonstration could be improved. The chemists’ findings were recently published in The Journal of Chemical Education

The traditional demonstration involves placing up to six open-flamed burners side by side on the laboratory bench. The instructor then adds different chemicals, by hand, to each flame. Depending on the solution added, the colour of the flame changes to fuchsia, lilac, red, yellow or blue/green.

“It’s a visually exciting and inspiring demo,” says chemistry lab manager Hamel Tailor. “Even though the American Chemical Society warns demonstrators to, ‘exercise extreme caution as flame jetting can occur, causing flames to shoot out 15 feet or more’.”

Canal agrees to its benefit as a teaching tool. “We surveyed two classes of third-year, non-science university students and found that after they viewed the demo, well over 60 percent had a greater understanding of energy transfer. They also had improved scores on standardized, short-answer exam questions.”

The chemists found they could improve the demo’s safety by using strips of insulating firebrick pre-soaked in salt solutions (instead of adding chemicals by hand), and by using a portable burner such as a butane/propane camping stove as the flame source.

 “The most significant hazard of this demonstration was eliminated by removing flammable solvents that can be spilled or splashed in the demonstration area,” says Sharma.

Tailor adds he’s pleased they were also able to make the demonstration less wasteful and costly.

 

About Simon Fraser University:

As Canada’s engaged university, SFU works with communities, organizations and partners to create, share and embrace knowledge that improves life and generates real change. We deliver a world-class education with lifelong value that shapes change-makers, visionaries and problem-solvers. We connect research and innovation to entrepreneurship and industry to deliver sustainable, relevant solutions to today’s problems. With campuses in British Columbia’s three largest cities – Vancouver, Burnaby and Surrey – SFU has eight faculties, delivers almost 150 programs to over 35,000 students, and boasts more than 155,000 alumni in 143 countries. 

Simon Fraser University: Engaging Students. Engaging Research. Engaging Communities.