Sciences for the IB MYP 3: by Concept 1 How do we make it work? Activity: Heating up, cooling down ATL Information literacy skills: Collect, record and verify data Individually or in pairs: In this activity you will observe and measure energy changes in exothermic and endothermic reactions. You will need 3 × 100 ml beakers Spatulas Thermometer and stopwatch, or temperature sensor and datalogging device Aqueous (dissolved) citric acid (C6H8O7) Crushed limestone (calcium carbonate, CaCO3) Sodium bicarbonate (sodium hydrogen carbonate, NaHCO3) Dilute sulphuric acid (H2SO4) Dilute sodium hydroxide (NaOH) Experiment 1 1 Pour 50 cm3 of aqueous citric acid into a beaker. Measure the temperature of the acid. 2 Add 1 spatula of calcium carbonate and stir. Measure the temperature until the temperature of the solution has returned to the starting temperature. 3 Now add 4 more spatulas of calcium carbonate and stir. Measure the temperature as before. Experiment 2 Again, pour 50 cm3 of citric acid into a beaker. Measure the temperature of the acid. Repeat the procedure for experiment 1, but this time adding sodium bicarbonate (sodium hydrogen carbonate) instead of calcium carbonate. Measure the temperatures as before. Experiment 3 1 Measure 25 cm3 of dilute sulphuric acid into the beaker. Measure the temperature of the acid. 2 Now add 5 cm3 of sodium hydroxide. Stir and measure the temperature. 3 Repeat until you have added 30 cm3 of sodium hydroxide, measuring the temperature change for each additional 5 cm3. Hodder & Stoughton © Paul Morris and Patricia Deo 2017 1 Sciences for the IB MYP 3: by Concept Organize your results in a suitable table, showing units of measurement. Present your data using a graph. Hodder & Stoughton © Paul Morris and Patricia Deo 2017 2 Sciences for the IB MYP 3: by Concept Hodder & Stoughton © Paul Morris and Patricia Deo 2017 3 Sciences for the IB MYP 3: by Concept In a conclusion, summarize your findings in each experiment. State whether the reactions were endothermic or exothermic. ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ Compare the energy changes in each reaction. ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ Hodder & Stoughton © Paul Morris and Patricia Deo 2017 4 Sciences for the IB MYP 3: by Concept Evaluate your experiment. Could you have improved its accuracy or validity? State improvements you could have made. ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ Assessment opportunities In this activity you have practised skills that are assessed using Criterion C: Processing and evaluating. Hodder & Stoughton © Paul Morris and Patricia Deo 2017 5