What does a G12 student do in a lab experiment? Here is a glimpse of a lab report from a Kuei Shan student...
Claire is redoing a part of her G12 Chemistry internal assessment experiment. Her topic, research question, and lab procedure is below.
What is the activation energy of the decomposition of hydrogen peroxide catalyzed by manganese dioxide by measuring the time taken for 10 ml of oxygen gas evolved at different temperatures?
Topic: Activation energy and Arrhenius equation
Aims:
1. To investigate how catalysts change the activation energy required for the decomposition of hydrogen peroxide to occur.
Method:
1. Prepare a standard solution of hydrogen peroxide with a concentration of [number] M in a flask. Seal the flask to reducing the risk of hydrogen peroxide decomposing immediately.
2. Set the water bath to 298K.
3. Use a graduated pipette to measure 5cm3of MnO2and place it into a test tube.
4. Place the test tube in the water bath for 10 minutes to allow the temperature of the test tube and the contents to equalize.
5. Connect a rubber tube with a rubber bung to a graduated cylinder and place under water in a tank. Make sure there are no gas bubbles in the graduated cylinder.
6. Use a graduated pipette to transfer 10 ml of the prepared hydrogen peroxide solution into the test tube with the manganese dioxide.
7. Cover the test tube with the rubber bung connected to the rubber tube and start a digital stopwatch at the same time.
8. Record the time taken for 10 ml of oxygen to evolve using the stopwatch.
9. Repeat steps 3-8 four more times to reduce the impact of random errors.
10. Repeat steps 3-9 for the following temperatures:
