Follow the instructions and fill in your RecordingSheet (Word 35KB) as you go.
Adaptation for ESOL students: Discuss in groups what is happening. Why do you think it didn't happen until you put the mixture into your mouth? Discuss in pairs/groups which of the ingredients are reacting together to cause the fizzing. To do this, you could mix combinations of two ingredients together and add water. Record these reactions. Discuss your results as a class. Teacher models writing an explanation of the experiment. You might like to use the writing frame for all or some students to scaffold their written work. A generalised experiment WritingFrame (Word 20KB) or a more ScaffoldedWritingFrame (Word 23KB) is available.
Taste tests are unusual in science experiments. You should do a taste test only if you are absolutely sure that what you are tasting is harmless, for example, a known food substance.
Students should conclude that the citric acid and tartaric acid are reacting with the baking soda to cause the fizzing. Students could then go on to test whether other substances, apart from sodium bicarbonate, fizz with an acid. They could also investigate rates of reaction by diluting the citric or tartaric acid or by varying the temperature.
Adaptation for ESOL students: Write a paragraph explaining what you did in your group and what happened as a result. Use the writing frame activity (Word 22KB) or experiment chart as a model. Teacher modeling may be necessary for some students. Students could also look at the previous explanations they have written. A scaffolded experiment chart is also available.
Although these are very simple demonstrations, they are spectacular and very effective for showing that something tangible is actually produced in the reaction. That "something" is carbon dioxide (CO2), which has its own properties and uses.
In this activity, as well as letting the carbon dioxide blast the cork from the bottle, allow the carbon dioxide to build up and then pull the cork out by hand. The children then get to hear the hiss of escaping gas and possibly actually see the carbon dioxide in a vapour. Teachers could make links for students with the processes that occur in a combustion engine (as an extension of this idea).
The cork exploding from the bottle could injure people nearby. Make sure that you stand well clear.
Adaptation for ESOL students: Write an explanation of what you did for this activity and what happened. If required use the experiment chart to record your ideas. What does this activity show about acids and bicarbonates?
Published on: 09 Jan 2018
