This lab is always a favorite! The colors burst and swirl in wonderful patterns and the students are usually in awe. They are curious and ask all those wonderful science questions... how, why, & what.
I use this as one of my 'learning how to do lab' activities. After students successfully complete their Lab Safety Test, I plan a week of labs. It is a time to learn how to properly handle materials, to complete lab write-ups and to work in groups. I like to select relatively easy labs that allow time to stop what is happening and dwell on procedures.