This is a very fun messy play activity which will amaze children of all ages. It's a great way to explore colour mixing and simple science as well as being a really fun sensory experience.
Time: 30 minutes
Age: Any age
Box of bicarbonate of soda (baking soda)
Two shallow boxes (e.g plastic box or cut down some old cardboard boxes like we did)
Empty spray bottle
Pour a layer of baking soda in to the bottom of each box. It doesn't matter too much how much you put in as long as you have a decent layer covering the bottom.
Layer of baking soda in the bottom of a shallow tray
Pour some vinegar into some plastic cups and add a few drops of food colouring to each to give a range of different colours
The kids can now pour the vinegar cups slowly into one of the boxes adding a little at the time to different parts of the box.
The bicarbonate of soda will bubble and fizz. Kids will enjoy watching the colours move, bubble and merge.
The fun begins
Watch the colours fizzing, flowing and mixing
Pretty bubbling colour swirls
My daughter then wanted to get her hands into it at the end and squeeze the mixture through her fingers. It was an interesting sensory experience as it felt wet and gritty
Get stuck in with hands at the end for fun sensory play
In your second box, try using a spray bottle instead. Pour some vinegar into the bottom of the spray bottle and add a few drops of food colouring.
Spray the coloured vinegar onto the bicarbonate of soda in the tray and watch the fizzing and bubbling
Watch the colours bubble and fizz
Add a few drops of a different colour of food colouring to the spray bottle to get a different colour.
We started with yellow then added a few drops of red to get orange, then added blue to end up with a green coloured mix in our box. With older children, try to predict what colour you will get before you spray.
The spray bottle trigger is also good for practising fine motor skills
Add different colours to the bottle to explore colour mixing
Get stuck in with hands at the end, squeezing the paste
We had added less vinegar with the spray bottle and the paste at the end was drier and grittier than with the first box
How does it work? The acetic acid in the vinegar reacts with the alkaline sodium bicarbonate in the baking soda to form sodium acetate, water and carbon dioxide. The bubbles you see are from the carbon dioxide gas escaping the solution.