Raising Raisins – a baking soda experiment

When you put raisins in glass of water, what happens?

They sink of course.

So is it possible to make those raisins rise to the top?

Yes indeed. In this simple baking soda  experiment.

For this, you will need,

A pint glass

Warm water

Raisins

Bicarbonate of Soda (Baking Soda)

White Vingear

Food colouring

Make a raisin dance

Method

Fill the glass half full with warm water

Add a drop of food colouring to tint the water. (This has no scientific bearing on the experiment other than I like things to look pretty!)

Add two heaped teaspoons of Bicarbonate of Soda.

Add a few raisins

Put the glass in a tray (just in case is overflows!)

Top of with white vingear

Watch the effect

You should see the raisins begin to rise and fall

Make a raisin dance

The science bit 

The vinegar and bicarbonate of soda reacted to form carbon dioxide as one of the products. The carbon dioxide bubble collect over the many surfaces of the raisin. Because carbon dioxide is lighter than water it rises to the top and takes the raisin with it. As the bubbles pop at the surface the raisin descends, only to be covered in bubbles gain at the bottom until the reaction finishes.

Can you think of anything else this would work with?

Related posts

More Baking Soda Experiments

Monster Tea Party

Baking Soda powered boat

Baking Soda Volcano

Baking Soda Popper

Fizzing rocks with baking soda

 

There are 5 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! 🙂

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