electrolysis

Build Your Own Hoffman Apparatus

Chad Hustings blogged this past school year about building his own Hoffman apparatus for each group of students. I have been using a Hoffman apparatus that had been purchased by my district before I began teaching there over 20 years ago to demonstrate electrolysis of water, but providing each student group with the ability to perform an electrolysis themselves is a powerful activity. I have used a different version of a homemade Hoffman apparatus, but after reading Chad's blog post, I decided to use a version close to his.  

Time required: 

If the Hoffman apparatus is built ahead of time (this takes about 5 minutes for each one if the teacher builds them), then the activity and discussion should take less than a 45 minute period.  

Hoffman Apparatus on the Go....

There are many places online to build a DIY Hoffman apparatus. The ACS offers an electrolysis of water lesson that includes a hand made Hoffman apparatus(link is external) as part of a unit on energy that I used as a resource.