Squirty Chalk Experiment

You will need

  • 2 x empty squirty bottles
  • Bicarbonate of soda
  • Cornflour
  • White vinegar
  • Food colouring
  • Water


  1. Label the two squirty bottles A and B
  2. Remove the lids from both bottles
  3. Add bicarbonate of soda to bottle A until it is one-third full 
  4. Add cornflower to bottle A until another third is full - the bottle should now be two-thirds full
  5. Add a few drops of food colouring to bottle A
  6. Fill the remainder of bottle A with water
  7. Fill bottle B with white vinegar
  8. Add a few drops of food colouring to bottle B
  9. Securely replace the lids on bottles A and B and shake hard!
  10. Squeeze bottle A to draw a picture on the ground 
  11. Trace the picture with bottle B to see the fizzy chemical reaction!

Top Tips

  1. Use your squirty chalk outside - a flat even surface works best
  2. The squirty chalk can be easily washed away with water
  3. Wear clothes you don't mind getting messy
  4. Try using different food colourings in each bottle for a rainbow of fun!
All The Let's Go Club
Are you ready to try CBBC?