Leading Teacher: Explicit teaching of enquiry skillsS.Hadfield

Lesson Plan: Indigestion tablets (what should the pH of the stomach be to stop indigestion?)

Year Group: 7 / Unit: 7E Acids and Alkalis
Aspect of Sc1: Planning and Obtaining / NC ref: Sc3 3f
Ability Range: Levels 3-6
Objective(s): To explain which cure for indigestion works best and why
Pupil Outcomes:
  • To predict which of the cures will work the best
  • To control the variables and make the experiment a fair test (optional)
  • To obtain evidence to test the prediction made

Lesson Outline / Activity / Additional information
Prior learning / Pupils should know that the conditions in the stomach need to be acidic. Pupils should also have a basic knowledge of neutralisation reactions.
Main / Question pupils understanding of indigestion, in particular the presence of acid in the stomach.
Present pupils with the slide on the claims of the three potential cures. Pupils are to use this information to make predictions on which cure will be the best.
Pupils are to carry out the experiment as detailed on the method slide, making sure that they record their evidence.
Pupils are then to reflect on their predictions made before the experiment in small groups ready for the plenary. / If the fair test outcome is being used it is important that the test tubes obviously contain different amounts of powder as this forms a key discussion point in the plenary.
Plenary / Discuss the concept of the ‘best’. More able pupils will recognise the need for the stomach to remain acidic to work, whereas less able pupils will probably argue for the cure with the most alkali to neutralise all the acid. / Will the stomach function correctly with no acid at all (once it has all been neutralised).
Technicians notes / The recipe for the three indigestion powders are:
Brioschi 10% by weight sodium hydrogen carbonate 90% NaCl
Rennie 10% by weight sodium hydrogen carbonate 90% NaCl
Pept-Eez 10% by weight sodium hydrogen carbonate 90% NaCl
To make sure you get the results required add one spatula of Brioschi, one spatula of Rennie (large) and two spatulas of Pept-Eez. This should give an acid (red), weak acid (yellow) and neutral (dark green) respectively.
To allow pupils to complete the tasks the three test tubes are best prepared and labelled for them.