What happens when
materials are mixed?
The PowerPoint about vinegar and baking soda.
The basic information for my task
 When you mix vinegar with baking soda it makes an
irreversible change. Irreversible means it can’t be turned
into it’s original form by physical methods. For example,
centrifugation, distillation and evaporation.
What do you do with these
physical changes?
 All of the methods I mentioned earlier are the ways of
physical change. Centrifugation is done by spinning the
mixture rapidly in a circle separating the components.
Distillation is a process of separation of different liquids
based on the differences in their boiling points.
Evaporation is done by separating the substance by
heating and vaporizing.
My experiment
 The aim of my experiment was to find out what
happened if I mixed vinegar and baking soda. I tried to
find out if it got colder or hotter or made any other
changes. Using exactly five grams of baking soda and
ten millilitres of vinegar I found out it got colder every
five seconds it dropped in temperature from about 19
degrees to 16. It caused a chemical reaction and
released carbon dioxide and the liquid rose.
More information
 The reason for it getting colder was because of
endothermic reaction. Endothermic means absorbing
energy, in these cases heat. What actually happens, is
the acetic acid (the thing that makes the vinegar sour)
reacts with the sodium bicarbonate (a compound in
baking soda) this forms carbonic acid. Carbonic acid is
used in the making of soft drinks, inexpensive and
artificially carbonated sparkling wines and other bubbly
drinks. Carbonic acid is unstable and it immediately falls
apart into carbon dioxide and water. The bubbles you
see from the reaction comes from the carbon dioxide
escaping the solution that is left. Carbon dioxide is
heavier than air, so it flows almost like water when it
overflows the container.
Conclusion
 This brings me to the end of my presentation about
vinegar and baking soda. I hope you learnt a lot about
endothermic reactions and different ways of separating
solutions.
Thank you for listening
Reference
 Science study guide (Geoffrey Thicket and Jim Stamell
2011), (en.Wikipedia.org), (Anne Marie Helmenstine),
(www.bbc.co.uk)