Experiment: Calorimetry & Hess's Law

Pre-Lab

Title: Determination of the Enthalpy of reaction for the burning one mole of Mg in O

Procedure:

1. We will measure the volume of solution which is placed in the calorimeter using a graduated cylinder.

2. Add 150 mL of water to a 400 mL beaker and add heat to start from 50 to reach 60C

3. Measure the temperature of the 50 mL of cold water which is in the graduated cylinder and then place it the calorimeter cup, write down when the temperature of the cold water is constant for 3 or two times readings every 30 seconds intervals.

4. Measure the 50 mL of the hot water in the graduated cylinder

5. Return the thermometer to the calorimeter cup and measure the temperature for three times every 30 seconds. Record the measurements.

6. Record the temperature of the hot water

7. Lift the Lid of the calorimeter and add the 50 mL of the hot water in it while mixing continuously.

8. Again record every 30 s until 10 min have elapsed.

9. Dispose the water in the sink and repeat part A of the experiment

10. Part b of the experiment

11. Clean the calorimeter cup and add 100 mL of the 1.0 M HCL to the cup

12. Weigh the four pieces of the Mg metal to the closest 0.001 g.

13. Record temperature in the calorimeter cup each 30 s intervals using a thermometer

14. Lift the Lid of the calorimeter and add the Mg pieces in the mixture and mix continuously.

15. Record the Temperature of the mixture every 30 s until 10 minutes have elapsed

16. Dispose the waste in the appropriate jar and dry the calorimeter cup

17. Experiment part C

18. Add 100 mL if 1.0 M HCl to the calorimeter cup and then weigh approx. 0.5 g of magnesium to the closest 0.001 g using a weigh boat (Be Careful while using the MgO powder)

19. Record the temperature of the calorimeter cup every 30 sec interval

20. Lift the Lid of the calorimeter and add the MgO in the Cup, then mix continuously.

21. Record the temperature every 30 sec until the 10 minutes have elapsed

22. Dispose the solution in the appropriate waste jar and clean the calorimeter cup