🔬 Science Activity

Acid & Base Indicator

Use purple cabbage juice to test acids and bases at home. A facinating chemistry STEM activity for preschoolers and school children.

🎓 Grade ⏱ 30–45 min ⭐ Easy 👨‍👩‍👧 Adult supervision needed
🔮
📋 How to Do This Activity
1
Step 1

Boil or blend purple cabbage with water to extract the purple juice — this is your indicator.

2
Step 2

Pour the cabbage juice into three separate plastic cups.

3
Step 3

Add white vinegar to the first cup (acid) — observe the colour change to red-pink.

4
Step 4

Add baking soda solution to the second cup (base) — observe the colour change to green.

5
Step 5

Leave the third cup as neutral — compare all three colours and discuss the pH scale

🧠 What Your Child Will Learn
🧪
Acids & Bases

⚖️
pH Scale

🌿
Natural Indicators

⚛️
Chemical Reactions

⚠️ Safety Notes
• Do not taste or consume any of the mixtures
• Handle vinegar carefully — avoid contact with eyes
• Adult supervision needed when boiling cabbage for juice extraction
• Dispose of mixtures by washing down the sink with plenty of water
📚 School Board Alignment
School Board Topic Covered Grade
NCERT/CBSE Acids, Bases and Salts Grade 5–6
Samacheer Kalvi Acids and Bases Standard 5–6
Cambridge Materials and their Properties Stage 4–5
Oxford Chemistry, Materials Grade 5
Try This With STEMLab! 🚀

Want your child to do this activity with expert guidance? Register for our STEM programme or the Math Model Makers Competition 2026.

📋 Register Free
📋 Register Now