by: Donna Giachetti
In a February 2014 blog post we said goodbye to the last of our goldenrod paper supply, a beloved staple in many science teachers’ classrooms.
Color changing goldenrod paper has been exciting students of all ages for decades to the wonders of chemistry! Imagine the enthusiasm of the first student or teacher who spilled a few drops of ammonia on a piece of yellow paper and observed it turn bright red! One can only image them exclaiming: “Super, Wow, Neat!!!”
Place the paper in a solution of household baking soda and the paper turns red; immerse it in vinegar and the red turns back to yellow! This goldenrod paper is colored with a dye that is an acid/base indicator: red in base and yellow in acid. The paper is similar to litmus paper that is blue in base and red in acid. Read the rest of this entry »