Measuring The Heat of Decomposition of Hydrogen Peroxide - Lab Report Example

The objectives are threefold: to measure the temperature change of a H­2O2 solution as it decomposes, to measure the amount of heat absorbed by the calorimeter and finally to calculate the calorimeter constant and then use it to determine the enthalpy of decomposition. The Lab Quest unit was turned on and the temperature probe plugged in. A 150-mL beaker was wrapped in towel paper and then placed inside a 250-mL beaker. A piece of aluminium foil big enough to cover the top of the two beakers was cut.

25 mL of cold water was measured using a graduated cylinder and poured onto the 150-mL beaker.. 25 mL of hot water was measured into the graduated cylinder and the temperature measured. The temperature probe was placed into the cold water solution in the 150-mL beaker. The Lab Quest unit was then set up to begin recording the temperature by pressing the green button. 25 mL of the hot water was poured into the 150-mL beaker containing the cold water. The cup was then quickly covered with the aluminium foil.

The cups were periodically swirled to ensure the contents mixed. Temperature recording was stopped once the temperature began to decline for several minutes. The used water was then poured into the sink. The recorded temperature and time data were entered into an Excel spreadsheet. The steps above were repeated twice and the average value calculated. 250 mL of H­2O2 was obtained. The temperature of the H­2O2 ­was measured and recorded as the initial temperature of the solution and calorimeter.

The concentration of the H­2O2 was also recorded. 60 mL of 0.5M KI solution was obtained. 40 mL of the H­2O2 solution was measured into a graduated cylinder and the temperature probe plugged in. 10 mL of KI was measured into another graduated cylinder and then poured into the calorimeter and then quickly covered with an aluminium foil lid. The temperature probe was immediately inserted into the probe through a hole in the foil lid. The temperature recording