Kitchen Chemistry: Safe Colour-Changing Experiments

Learning Objectives

After completing these activities, children will be able to:

• Observe and describe color changes in simple chemical reactions
• Practice safe laboratory habits
• Develop prediction and observation skills
• Record experimental results through drawings or simple worksheets
• Use basic scientific vocabulary appropriate for their age

Safety First: Setting Up Your Kitchen Laboratory

Before diving into our exciting experiments, let’s establish some important safety rules that will protect our young scientists:

Essential Safety Rules

1. Adult supervision is required at all times
2. Wear protective equipment:
   • Child-sized safety goggles
   • Old clothes or an apron
   • Disposable gloves (optional but recommended)
3. Keep hands away from face during experiments
4. No tasting of experimental materials
5. Wash hands thoroughly before and after activities

Creating Your Science Space

Set up a dedicated area with:

• Easy-to-clean surface
• Good lighting
• Access to water
• Paper towels within reach
• Separate containers for materials
• Result recording sheets and colored pencils

Experiment 1: Rainbow Milk Magic

This beautiful experiment demonstrates how soap affects surface tension while creating stunning swirls of color.

Materials Needed:

• Shallow white plate or dish
• Full-cream milk (room temperature)
• Food coloring (red, yellow, blue)
• Liquid dish soap
• Cotton buds
• Stopwatch (optional)
• Recording sheet

Instructions:

1. Preparation
   1. Pour enough milk to cover the bottom of the plate (about 1cm deep)
   2. Let milk settle to room temperature
   3. Prepare recording sheet with “before” and “after” sections
2. Setting Up
   1. Place 4 drops of different food colours in a circle pattern in the milk
   2. Keep drops about 3cm apart
   3. Don’t stir or disturb the milk
3. The Experiment
   1. Dip a clean cotton bud in dish soap
   2. Carefully touch the soap-dipped end to the center of the milk
   3. Observe what happens for 30 seconds
   4. Try touching different coloured areas with a new soap-dipped cotton bud

Scientific Explanation (Kid-Friendly):

“The soap is like a tiny superhero that breaks up the milk’s special skin (surface tension). When this happens, the colors start to dance and swirl as they try to find new places to go!”

Extension Activities:

• Try with different types of milk (skim, full cream, soy)
• Use different temperatures of milk
• Create a “color mixing prediction chart”

Experiment 2: Red Cabbage Rainbow

This experiment introduces the concept of pH using a natural indicator from red cabbage juice.

Materials Needed:

• ¼ head of red cabbage
• Hot water (handled by adult)
• Ice cube tray
• Common household liquids:
  • Lemon juice
  • Vinegar
  • Water
  • Baking soda solution
  • Liquid soap diluted with water

Instructions:

1. Preparing Cabbage Juice (Adult Task)
   1. Roughly chop the cabbage
   2. Pour hot water over cabbage in a bowl
   3. Let steep until water is deeply coloured (15-20 minutes)
   4. Strain and cool completely
2. Setting Up Test Stations
   1. Label each ice cube compartment
   2. Add 2 tablespoons of cabbage juice to each section
   3. Prepare testing solutions in small cups
3. Conducting Tests
   1. Add one drop of test solution to each compartment
   2. Observe colour changes
   3. Record results through drawings or helper-written notes

Safety Notes:

• Adult handles hot water
• Keep solutions separate and clearly labeled
• No tasting or drinking of any solutions
• Wear protective goggles

Recording and Sharing Results

Simple Recording Sheet Template:

Create a sheet with:

• Space for experiment name and date
• “I think” section for predictions
• “I saw” section for observations
• Area for drawing results
• Smiley face scale for rating the experiment

Sharing the Learning:

• Create a family science journal
• Take before and after photos
• Make a simple video diary
• Share results with grandparents or friends online

Troubleshooting Tips

Common Challenges and Solutions:

1. Colors Not Mixing Well
   • Check milk temperature
   • Use fresh materials
   • Ensure correct quantities
   • Clean equipment between attempts
2. No Reaction Occurring
   • Verify material freshness
   • Check concentrations
   • Try new locations in the mixture
   • Ensure all steps were followed
3. Too Much Mess
   • Use smaller quantities
   • Place newspaper under work area
   • Keep paper towels handy
   • Use splash guards or trays

Extensions and Variations

For More Advanced Learning:

• Create a color wheel using reactions
• Time different color changes
• Compare different brands of materials
• Design new experiments with safe materials

For Different Learning Styles:

• Add movement activities
• Create sound effects for reactions
• Draw comic strips of experiments
• Build 3D models of observations

Additional Resources

Australian Science Education Resources:

• Cool Australia
• CSIRO Education Programs

Recommended Books:

• “Kitchen Science Lab for Kids” by Liz Lee Heinecke
• “Awesome Science Experiments for Kids” by Crystal Chatterton
• “The Everything Kids’ Science Experiments Book” by Tom Robinson

These kitchen chemistry experiments offer more than just colorful entertainment. They provide valuable opportunities for young children to:

• Develop scientific thinking skills
• Practice safety awareness
• Build vocabulary
• Strengthen observation abilities
• Experience the joy of discovery

Remember to focus on the process rather than the results and celebrate all observations and questions as valuable parts of the learning journey.