In this very interactive and hands on lab students will be testing 20 different solutions using litmus paper and using the pH scale to discover if they are an Acid, Base or Neutral. Every year my students vote this lab as being their favorite from throughout the entire year!
As a teacher all you need to do is print the lab, set out 20 different unknown solutions (about 100-150 mL each in their own individual beakers) and let the students get to work. It's awesome watching them test each solution, collect data and guess what they think each solution might be. The fun really comes the next day though when you reveal what each solutions really is and the official pH of each one.