Chemical Education Today
Puzzle: What’s Wrong in This Lab? Find the Problems in the Lab! photo by Jerrold J. Jacobsen
Identify as many unsafe or incorrect lab techniques as you can in the photos on the cover and at the right. Make a list and explain how each unsafe or incorrect technique should be done correctly. Teaching Precise Technique The incorrect and correct techniques shown below are a partial solution to the puzzle. They were excerpted from Chemistry Comes Alive! Volume 6 (CCA! 6), which will be published later this year by
JCE Software. CCA! 6 shows safe, correct lab techniques and also includes many improper techniques that you can use to test whether students know how to work in a lab.
A really unsafe lab.
Titration Techniques—Getting them exactly right is never easy.
Pipetting: Pipetting by mouth is never acceptable. Use a bulb instead.
Recording lab data: You have probably seen everything used, including a paper towel. But using a lab notebook is the way to do it.
Reading a buret: Not upwards, not downwards, but straight on.
Filling a buret: Never directly from a carboy. Pour from a beaker instead. photos by Jerrold J. Jacobsen
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Journal of Chemical Education • Vol. 79 No. 4 April 2002 • JChemEd.chem.wisc.edu
