Planning A Fair Investigation D. Crowley, 2008

Planning A Fair Investigation To be able to plan a fair investigation Monday, April 27, 2015

Indigestion You are going to carry out an experiment to identify which indigestion tablet is most effective Complete the indigestion worksheet during your experiment

Amount of acid needed to change methyl- orange red for different indigestion tablets Concentration of acid remains constant Experiment

Experiment 1. 1.Grind an indigestion tablet up using a pestle a mortar 2. 2.Place this into a test tube, adding 10cm 3 of water 3. 3.Now add 4 drops of methyl-orange to the test tube 4. 4.Add 1cm 3 of acid to the test tube using a dropping pipette, and record how much you needed to add before the methyl-orange changed from orange to red (make sure you stir the solution thoroughly) 5. 5.Repeat this experiment using the other two indigestion tablets

Extension Amount of acid needed to change methyl-orange red for a particular indigestion tablet Concentration of acid varied

Extension Experiment 1. 1.Grind an indigestion tablet up using a pestle a mortar 2. 2.Place this into a test tube, adding 10cm 3 of water 3. 3.Now add 4 drops of methyl-orange to the test tube 4. 4.Add 1cm 3 of acid to the test tube using a dropping pipette, and record how much you needed to add before the methyl-orange changed from orange to red (make sure you stir the solution thoroughly) 5. 5.Repeat this experiment using the other two concentrations of acid

Costing The tablets come in different quantities, and cost different amounts: - TabletQuantityPrice Per Tablet (Pence) Renne27ml4.1 Bisodol19ml3.2 Superdrug17ml3.1

Levels Level 4 – plan to change one variable, and prediction made Level 5 – recognition of factors which may affect the experiment, and a scientific prediction made Level 6 – explanation of how different variables could affect the experiment, and an accurate scientific prediction made