Learning Objectives:

     Students will be able to:

• Test common household substances and determine whether they are an acid or a base.
• Test common household substances and determine the pH of each and make comparisons.

• Information on the difference between an acid and a base.
• Information on a pH scale and what it indicates.

• Household items (vinegar, coca cola, milk, mouthwash, shampoo, Fantastik, tap water, grapefruit juice, dilute Draino, dilute Ammonia)
• Small plastic cups or vials
• Red and blue litmus paper
• pH paper (1 - 14)
• goggles
• paper towels

Teacher Preparation:

• Discuss information on acid, base and pH.
• Prepare household items in labeled cups for each group.
• Blue and red litmus paper AND pH paper for each group.
• Goggles for each student.
• Chart for recording predictions and results.

• Use goggles for this experiment!
• First, have students predict and record whether each item is an acid or a base and its pH.
• Use one strip of blue litmus and one strip of red litmus for each item.  Dip both strips into the cup to be tested.  Record the color of both strips (red/red = acid, blue/blue = base, red/blue = neutral) and determine if it is an acid or a base.
• Use one strip of pH paper for each item.  Dip it into the cup to be tested.  Compare the strip to the color chart on the pH vial and record the pH.

• Have students create a bar graph for the pH level of each item.
• Have students compare the items tested for acidity and basicity.  Are they harmful?  Which is the most acidic? basic?  What is the range and mean pH of the items tested.