This is a fun activity to get students thinking about the properties of acids and bases based on their prior knowledge. Then using what they know, can they figure out the rest of the properties?
I like to do this activity as a friendly competition and see how many each pair of students can answer correctly. Before the students place items into the Venn diagram, I ask them to look at the properties and write a red “A” next to the property if they think it belongs to an acid, a blue “B” if they think it belongs to bases, and “AB” if it belongs to both categories.
Once they have completed categorizing the properties on their own, have each student share their answers with their seat partner. What was the same? What was different? Have them discuss their reasoning for each answer and try to come to a consensus. (You can add an additional step by asking partners to compare answers with another set of partners.) When they are ready, reveal each answer, one at a time, and discuss. Students will write (or glue in) each property into the Venn diagram.
Please click on the tags below to find additional lessons on Acids, Bases, and pH.
Cabbage Juice in an Erlenmeyer Flask with a pipette
micro-wells or small clear bathroom cups
litmus paper – blue and red
beakers and pipettes for each solution
Substances to test – diluted in water
You can have all of these set up at one station and students can pick one up and take one to their desk for testing, then return it to the station and choose another substance- you don’t have to have a complete set for each group.
This classic interactive website is a great way to practice identifying acidic, basic, and neutral substances along with reading pH values. There are three different levels which increase in difficulty as the students complete each activity.
Challenge 1 – students have to identify and categorize the different ‘juices’ that they will serve to the aliens as either Acids, Bases, or Neutral.
Challenge 2 – students will practice serving requested juices to aliens, but if they serve a juice from the wrong category, aliens can become sick, or worse!
Challenge 3 – students have to change the pH values of the juices on the tray by either adding acids or bases to raise or lower the pH values.
I have a handout with instructions for the students to record their progress (worksheet)
Please note that the updated link is located at: (updated 3/4/18)