Background:

Bubbles form because of a combination of water’s hydrogen bonds** and the oily film you can see shimmer in the light. The oily film you see is actually two separate layers of soap attached to, and surrounding, hydrogen-bonded water. Adding sugar works with the soap to create an extra strong bubble. When you’re blowing a bubble inside of your first bubble, the original bubble expanded. When you blow your second bubble, you increase the volume of air inside both bubbles! The extra volume causes the creation of the second bubble whilst at the same time forcing the original bubble to expand. Luckily, the hydrogen bonds of the water (and their soapy, sugary friends) are very elastic and allow the volume to increase.

Equipment:

  • Measuring jug
  • x2 tablespoons
  • Mug
  • Washing up liquid
  • Sugar
  • Straw
  • Dinner plate or a clean, flat surface.

Method:

Fill a cup with 250ml of water. Add 2 tablespoons of granulated sugar to the water. Pour 2 tablespoons of washing up liquid into sugar water and stir until it has dissolved (30seconds). Smear a dinner plate with a thin layer of the mixture. Dip your straw into the solution in your mug. Then to blow a bubble on the plate. Dip the straw back into the solution and place the inside the first bubble. Blow a second bubble! See how many bubbles you can blow up inside the others.

Discussion/extension:

  1. How many bubbles inside a bubble can you make?
  2. Does changing the amount of sugar added affect the strength of the bubbles formed?
  3. Approximately what was the largest diameter of bubble you made?
  4. Use a different type of sugar e.g. granulated, icing, caster, Demerara- does this make a
    difference?
  5. Does using different temperatures of water affect the number of bubbles within bubbles
    you can form? Or the strength of the bubbles formed?

What makes the best bubble mix?

Tweet or email your ultimate bubble mixture recipe, conclusions or your findings to:
#chemistry4all #LJMU_CfA #bubbles4all chemistryforall@ljmu.ac.uk

** for information on hydrogen bonds go to:

http://www.bbc.co.uk/education/guides/zt9887h/revision/4

Click here to download PDF version of Bubble Trouble