REFERENCEGeneral Chemistry for Engineering and Science II- pages 79-94OBJECTIVESPractice obtaining calorimetry measurements and using the data to demonstrate Hess's law of combining enthalpies of reaction.QUESTIONDid your experiment demonstrate Hess's law of heat summary?DISCUSSIONFor this experiment we need to know what calorimetry, exothermic, endothermic, Hess's law and calorimeter are. Calorimetry is the measurement of the quantity of heat exchanged. Exothermic is a chemical reaction in which heat is produced, while endothermic is a chemical reaction in which heat is absorbed. Hess's law is the variation of heat in a chemical reaction that is the same regardless of the number of states the reaction is affected into. Finally, a calorimeter is a device used to measure the quantity of heat released or absorbed during a chemical reaction.CHEMICAL EQUATIONSHess's law: ΔH_N+ ΔH_S= ΔH_RTemperature change: Δt=t_final-t_initalMass of a solution: 2.05 g ×(1 mole)/ 40.00 g = 0.05125 mol NaOH Percentage error: % error = ((Sum of ΔH_(N ) and ΔH_S )-ΔH_g)/( ΔH_g ) × 100% PROCEDURE (See attached.) CALCULATIONS (See attached.) RESULT HYPOTHESIS If the experiment demonstrated Hess's law of heat summation, then the ΔH_R will be equal to ΔH_N + ΔH_S. OBSERVATIONSIn this experiment, there were three different phases , phase one was A: Heat of neutralization ΔH_N, phase two was B: Heat of solution ΔH_S and phase three was C: Heat of reaction ΔH_R. The first phase consisted of four steps and started with 50 mL of 1.0 M HCL and 50.0 mL of 1.0 M NaOH measured and transferred to two different calorimeters. The two substances placed in the calorimeters had no color. Then from minute 1 to minute 4 the temperature of HCL was...... middle of paper ......nt I was able to calculate the value of ΔH_R using Hess's law of ΔH_N+ ΔH_S = ΔH_R.CONCLUSIONBased on the objectives, question and results of the experiment I can say that I achieved the objectives of this laboratory. I also believe that my results justify the position I have taken on the following hypothesis: if the experiment demonstrated Hess's law of heat summation, then the ΔH_R will be equal to ΔH_N + ΔH_S. My data justifies this because I was able to take the information from phases A, B and C to calculate ΔH_R with Hess's law. In the end, ΔH_R had a value of -19,095.78 cal/mol (ΔH_R). However, when Hess's law was used, ΔH_(R) was equal to ------------21109.72 cal/mol and from there I calculated the percentage of error and it was 10.55%. I believe my data supports my hypothesis because I was able to correctly determine the ΔH_R in the experiment using Hess's law.