Raising Raisins – baking soda investigation

What do you think will happen if you put a raisin in a glass of water?

It will sink!

Do you think it’s possible to make raisins rise to the top and jump around?

Raisins Dance challenge

Find out in this simple baking soda investigation.

What you need:

A pint glass

Warm water

Raisins or anything else you would like to test.

Bicarbonate of Soda (Baking Soda)

White Vinegar

 

Raising Raisins Instructions

Fill the glass half full with warm water.

Add two heaped teaspoons of baking soda.

Add a few raisins

Put the glass in a tray – it might overflow

Top of with white vinegar

You should see the raisins begin to rise and fall

Make a raisin dance

Why do the raisins dance?

The vinegar and bicarbonate of soda react forming carbon dioxide. The carbon dioxide bubbles collect over the surface of the raisins. As carbon dioxide is lighter than water it rises to the top and takes the raisins with it. As the bubbles pop at the surface the raisins drop again, only to be covered in bubbles again at the bottom until the reaction finishes.

More Investigation Ideas

Can you find the smallest amount of baking soda and vinegar that allows the raisins to dance? Try with just one raisin and then investigate to discover if you need more to make 2 raisins dance.

Can you think of anything else this would work with? You could investigate using other dried fruits and record how well each dances.

We tried with small LEGO pieces and found that they sank when they filled with water and once the reaction started they jumped to the top, but didn’t dance around.

We then tried with small coins, but these didn’t move at all, you can see how all the bubbles of carbon dioxide have gathered on the surface though.

carbon dioxide on a coin

Another idea is to attach something to the raisins and see if they still dance.

Why do baking soda and vinegar react?

If you combine an acid ( vinegar ) and an alkali ( baking soda ) they react together to neutralise each other. 

The reaction releases carbon dioxide gas, which is the bubbles you see.

Dancing Raisins

More baking soda investigations

More Baking Soda Experiments

Monster Tea Party

Baking Soda Powered Boat

Baking Soda Volcano

Baking Soda Popper

Fizzing rocks with baking soda

 

There are 6 comments

  1. Andrea @ No Doubt Learning

    Such a great experiement! We did this awhile ago on a smaller scale (just using water and letting the raisins sit overnight) and my daughter was amazed that they could float! Just found your site and am off to take a look around! 🙂

Post Your Thoughts