Chemistry 1 Lab Report

Experiment 12 Calorimetry and Hesss Law Purpose The purpose of this lab is to determine the enthalpy of chemical reaction for the burning of one molee of magnesium in oxygen. Although the reaction is exothermic, the ? HRXN go away be determined by exploitation calorimetry and then using Hesss Law to manipulate the data collected to yield the answer needed. Procedures Dillon, Stephanie. Calorimetry and Hesss Law. Laboratory Manual. Pearson Publishing, 2012, pp. 168-177. Data and Results dismantle A ledger of iciness pee 49. 9 mL Temperature of stale water (in transfuse) 23. 50 C Volume of hot water 49. 9 mL Temperature of hot water(in cup) 550 CPart A Calculations Mass of cold water 49. 9 g Tf from interpretical record by extrapolation 34. 90 C ?THW for hot water -20. 1 ?TCW for cold water 11. 4 qHW for hot water -4196. 5 J qcw for cold water 2380. 1 J qCal for the cup 1816. 4 J Ccup for the cup 159. 3 J Part B Description of sample surface fizzed when dissolved in HCl Vo lume of HCl 100 mL Initial Temperature 220 C Mass of Mg 0. 1485 g Part B Calculations Tf from graph 50 C Mass of HCl 100 g ?TCW for HCl -2092 J qHCl for solution -204. 4 J qCal for cup -2296. 4 J qRXN -47594 J ?HRXN for Mg web REACTION 2HCl(aq) + Mg(s)>MgCl2(aq) + H2(g)Part C Description of sample Volume of HCl 100 mL Temperature of HCl 220 C Mass of MgO 0. 5052 g Part C Calculations Tf from graph 240 C ?TCW for HCl 1. 50 C qHCl for HCl 627. 6 J qCal for cup 61. 32 J qRXN 608. 92 J ?HRXN for Mgo 55469 J/mol Net Equation 2HCl(aq) + MgO(s)>MgCl2(aq) + H2O(l) Calculations windup In this experiment we had to find the wake up capacity of the calorimeter cup using two trials of hot and cold water. When we obtained the data after 10 proceedings of recording 30 second intervals of the calorimeter cup temperature, we created a line graph to show the trend line.Read this Practice Test Chem 105With the trend line, we could run into out the final temperature and delta H in the proce ss. With the equation we could find the set off of reation for hot water q HW = m c DTHW and using qCW = m c DTCW we could find the heat of reaction for cold water. By using qHW = qCW + qCal, we post find the heat of reaction of the cup and multiply that by the sort in temperature to find the heat capacity. After placing Mg into HCl and then the analogous thing with MgO, we could find the heat of solution of HCl with q CW = m c DTHCl.When we strand the values of DHRxn for B and C we can use Hesss Law, which is shown in the calculations section. on the whole the data is in the data section of the report. The percent error of Mg was about 30%. The actual value of Mg was 601200 J/mol and the experiment we obtained was 420611 J/mol. There could drive been human error in order to obtain the results that could have accounted for the 30% error, although this is not so high. Also, the heat of formation we used was MgO(s) for the actual value, although in the experiment it was a gas. This could have also accounted for some error.