The Lab Quest had to be adjusted so that the interval was 15 s/sample and so that the duration was 480 seconds. The calorimeter was then constructed by staking two Styrofoam cups together and lacing them in a 400 mL beaker. 100 mL of 6M HCl was added to the Styrofoam cups and the initial temperature was recorded by the lab quest. One gram of MgO was weighed out using scale and watch glass and all weights were recorded in table 2. After the initial temperature was recorded the MgO was quickly added and the cup was swirled while the temperature changes were recorded. After the data collection as over the reaction stopped the reaming MgO residue on the watch glass was recorded and all waste products were disposed of and all material were cleaned. The data form reaction four was saved on the lab quest so that reaction five could be carried out. The Styrofoam cups were restacked and placed in a 400 mL beaker to which 120 mL of 2M HCl was then added the calorimeter was then closed and the initial temperature was recorded by using the lab quest. 0.5 g of Mg was then gathered and weighed using the scale and watch glass, all weights were recorded in table 3. Once the initial temperature was recorded 0.5 g of Mg was quickly added to the Styrofoam cup and the calorimeter was then swirled while the reaction occurred and the temperature changes were …show more content…
The theoretical value for enthalpy calculated using the given values table 5 was -55.22 kJ. The enthalpy of reaction three calculated using the experimental data or the temperature changes recorded was done by using “q” values and limiting reactant molarity and thus that value was found to be -60.70 kJ. The third calculation using Hess’s Law of summation was found using the experimental enthalpies for reactions one and two which were then combined to calculated a value for reaction three of -55.68 kJ. The actual experimental data was shown to be much higher than the other two calculations. The summation calculation was actually closer to the predicted value despite using experimental data. This could be due to inaccurate temperature measurements or slightly larger amounts of reactants added, however, the values were reasonably close together and can thus be considered