What you'll need
Bicarbonate of soda
A powder that looks similar to bicarbonate of soda
E.g. flour or icing sugar
A plastic drinks bottle
A balloon or plastic bag
If using a plastic bag, make sure it doesn't have any holes in it.
A hair tie
If you're using the plastic bag
Pour vinegar into the plastic drinks bottle
Pour until it is around 2-3cm full.
Make a funnel
Make a funnel with a piece of paper and use it to put two spoons of bicarbonate of soda into the balloon/ plastic bag.
Fasten the balloon or bag
Fasten the neck of the balloon around the rim of the drinks bottle, or the plastic bag using the hair tie, careful to not let any of the powder fall into the vinegar yet.
Upend the balloon or plastic bag
Upend the balloon or plastic bag quickly to let all of the powder fall into the vinegar, whilst keeping it sealed around the rim of the bottle.
Watch the balloon start to inflate!
Try other ingredients
Try this experiment again with another powder which look similar to bicarbonate of soda e.g. flour or icing sugar. Does the balloon still inflate?
- Chemical reactions happen when chemicals, (e.g. the acid ‘vinegar’ and the base ‘sodium bicarbonate’) are changed into something new, in this case, a gas – carbon dioxide, which blows up the balloon.
- When you substitute the sodium bicarbonate with something that looks similar, icing sugar, the reaction doesn’t work anymore because the icing sugar doesn’t have the same chemical properties as the sodium bicarbonate.
Real life science at the Crick
Acids can also be found in living things. For example, chemical reactions involving amino acids are needed for growth, including of the bacteria that cause disease.
Scientists at the Crick are investigating how the bacterium that causes the disease tuberculosis (TB) can be killed by antibiotics. Scientists have found that tuberculosis can be treated by giving people a drug that looks a lot like the amino acid the bacteria need to grow.
But just like in our experiment, even though it looks similar, this time the chemical reaction doesn’t work so the bacteria can’t grow properly. By understanding this process, scientists can design better drugs to treat TB.