creativeminds
Investigate!
Soda Science
Often fizzy drinks are served at a party. If they are left
uncovered for too long the bubbles 'disappear’ and they
become flat.
You must discover how long it takes for a drink to become flat, the
best way to test this process and to see if ice in a drink affects the
rate of bubble disappearance.
You have
Cups or bowls
A selection of fizzy drinks, cola, water, diet drinks etc.
Timer
Paper
Newspaper
Ice cubes
Activity
If you add sugar or salt to water and stir, the crystals dissolve in the water to produce a
clear colourless solution. Gases can also dissolve in liquids to form solutions. The fizz in
fizzy drinks is actually carbon dioxide gas that has been pumped into the drink at high
pressure. The gas particles are forced to mix and mingle with the water particles. The
bottle or can is then sealed so that there is a higher pressure in the can or bottle than
outside. The pressure is released when we open the drinks and the carbon dioxide
appears in the drink as lots of tiny bubbles or 'fizz'.
You have to design a way of measuring the 'fizz' in drinks and how it changes over time.
Here are some ideas that you might try.
•
Count the number of bubble on the surface at given time intervals. You may need
to take a digital photograph of the surface and use that to count the bubbles as
they are constantly changing.
•
A taste test, where you rate the 'fizz' in your mouth on a scale of 1 (not fizzy at all)
to 5 (extremely fizzy). In this test it is important that the same person tastes each
time as it people's opinions can vary, you may want to appoint a tasting panel.
•
Your own idea.
1.
Take your first reading at 0 seconds, then at 3,4 or 5 minute intervals, as you
decide, until the drinks are completely flat.
2.
When you have decided the method that you want to use, experiment with a
variety of drinks to see which looses the fizz fastest. You might like to compare the
following types of drinks
creativeminds
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3.
Investigate!
Diet and regular
Naturally and artificially carbonated
Drinks with and without ice.
You can record your results on a table or graph and discuss with your group.
Useful Questions
•
Why do you think a can of fizzy drink almost seems to explode on opening if it is
shaken up before? What could you do to prevent this?
•
Does ice make the drink become less fizzy more quickly or not? Why do you think this
is?
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What do you think is meant by 'naturally carbonated’? Can you find out?
What do you think would happen to the 'fizz’ of the drink if it was heated?
Try adding a few raisins to a clear fizzy drink, what can you see happening? Why do
you think that is? (The raisins rise and fall as the bubbles of carbon dioxide attach to
them and make them float, then when they reach the surface the bubbles burst and
the raisins sink.)
Research Opportunities
•
Joseph Priestley, who was born in Yorkshire, is one of the first people to explain what
made fizzy water 'fizz'. Find out as many facts as you can about this remarkable man
and plot his life on a time line. List in order of importance his most significant
discoveries. Can you justify your judgements? How have the discoveries that he made
over 200 years ago affected our world today? Why not try and copy one of his
experiments?
•
Make your own lemonade using water, bicarbonate of soda, icing sugar and lemon
juice.
•
Add 2 tablespoons of icing sugar and 4 teaspoons of bicarbonate of soda to a
jug of water.
•
Mix well until dissolved.
•
Add 3 tablespoons of lemon or lime juice. (you can use powdered citric acid)
The liquid will fizz as the citric acid in the lemon reacts with the bicarbonate of soda to
produce carbon dioxide gas bubbles. Drink quickly as the bubbles are not pressurised
and will not last too long. You could compare your lemonade with manufactured ones
on the criteria of taste and 'fizz'. Design an advertisement for your drink.
•
Try dropping a spoon of ice cream into a glass of cola or lemonade. What do you
observe? Why do you think this is?
Useful Websites
This website will show you some of Joseph Priestley's inventions and tell you a little about
his life.
http://inventors.about.com/library/inventors/blJosephPriestley.htm
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Investigate!
This website will give you a quick history of lemonade and information on lemonade from
around the world:
http://en.wikipedia.org/wiki/Lemonade
Use this site to discover why milk is good for you and great fun too!
http://www.got-milk.com/
The Creative Minds project works with museums libraries and
archives across the Yorkshire region, to provide young people with
learning opportunities in Science, Technology, Engineering & Maths
(S.T.E.M.). This ground-breaking project is the first of its
kind in the country and is managed by MLA Yorkshire. This
pack was developed by Creative Minds and Eureka! The
Museum for Children with funding from Yorkshire Forward.