Mai Lesson

Crack the pH Code

Science · 30 min · Ages 12-15 · Middle school · You and your child together

This lesson challenges learners to become 'pH Detectives' using a homemade indicator to classify common household liquids. They'll explore the chemical properties of everyday substances and understand the concept of pH.

What your child gets out of it

• Construct a natural pH indicator using red cabbage.
• Classify household substances as acids or bases based on color changes.
• Explain the importance of pH in everyday life and various applications.

What you need

• Red Cabbage — Steep in hot water 10-15 min, then strain and cool before the lesson. (or Blueberries, Grape Juice)
• Hot Water — Used to extract the indicator from red cabbage. Can be heated in a kettle or microwave.
• Bowl — For steeping the red cabbage. (or Large Pot, Pitcher)
• Strainer — To separate the cabbage solids from the indicator liquid. (or Colander, Cheesecloth, Fine Sieve)
• Cup — To hold the prepared cabbage indicator. (or Glass, Mug)
• Small Cups — One for each household liquid sample. (or Shot Glasses, Jars, Clear Plastic Cups)
• Household Liquids — A variety of common liquids like lemon juice, vinegar, baking soda solution, soap, milk, etc.
• Indicator liquid

How it runs

1. Introduction · 5 min
2. Explore & Plan · 8 min
3. Discussion · 6 min
4. Activity · 9 min
5. Summary · 2 min