Classroom Lab Guide
Simple activities to bring the pH scale to life
1. Hidden Indicators
15 MinutesPredict and test the acidity of common kitchen items without looking at the labels.
Steps
- Set out 4 clear cups labeled A, B, C, and D.
- Place Lemon Juice, Milk, Water, and Soap Solution in the cups.
- Ask students to predict which is which using only their eyes.
- Use test strips to reveal the true pH of each.
Materials
- Universal pH Strips
- Transparent Cups
- Household liquids
2. The Buffet Effect
20 MinutesWhat happens when you mix an acid and a base?
Steps
- Start with a cup of Vinegar (acidic). Record pH.
- Slowly add a pinch of Baking Soda (alkaline).
- Watch the reaction (bubbles are CO2 gas!) and record the new pH once settled.
- Discuss how the pH moves toward neutral (7.0).
Materials
- Vinegar
- Baking Soda
- Safety Goggles
Teacher Note: Safety First
Even household liquids can be dangerous if misused. Always direct students to never taste lab samples, wash hands after handling, and wear eye protection when mixing substances. Crucially: supervise any activity involving cleaners like ammonia or bleach to ensure they are never mixed.