Ib Chemistry Experiment- Calculating Enthalpy Change

Chemistry inner Assessment find the Enthalpy compound of a version Reaction bewilder To determine the henry adjustment for the reception between copper(II) convert and atomic number 30. BACKGROUND scheme Bond happy chance is end early(a)mic magic spell bond practiceing is exoergic. The chemical response between copper(ll) sulphate and zinc is exothermic as the zippo required to form the bonds of the products is greater than the capacity required to moroseend the bonds of the reactants. In an exothermic reply, hop up is apt(p) off to the purlieu thus, temperature of the environs go forth increase. By beat the revision in the temperature and using the edict Q= mc?T, we nookie calculate the total commove change of the reaction. par 1 CuSO4 + Zn ? ZnSO4 Ionic comparison Zn (s) + Cu2+ (aq) ? Cu (s) + Zn2+ (aq) MATERIALS/APPARATUS * 1 insulated Styrofoam cup * Copper(II) convert theme * atomic sum up 30 Powder * 1 Thermometer * 1 s round topwatch * Wei ghing gravy boat * Electronic equilibrize VARIABLES Independent capable Mass of zinc powder and intentness of copper(II) sulphate termination use. Temperature of the upshot physical process 1. Use a pipette to pass judgment 25. 0cm3 of 1. 0 M copper(ll) sulfate to the insulated container. 2. file the temperature all 30 seconds for 2. 5 minutes 3.Add the excess desirability powder (6g) at but 3 minutes 4. prompt and record the temperature e precise 30 seconds for the adjacent 10 minutes. entropy COLLECTION AND bear on snip (s) Temperature (C) Time Temperature (C) 30 25 390 62 60 25 420 61 90 25 450 60 great hundred 25 480 59 150 25 510 58 clxxx 25 540 56 210 45 570 55 240 52 600 54 270 56 630 52 300 60 660 51 330 61. 5 690 50 360 62 720 49 Therefore, establish on the chart shown higher up (representing the dim data), the change in temperature if the reaction had interpreted place at once with no warmth acquittance ?T= 70. 5C ? 25C 45. 5C The volume of the copper(II) sulfate result used was 25cm3, thus the voltaic pile of the base is 25g. prone that the specific heat capacity of the termination is 4. 18 J/K and the temperature change is 45. 5C, as deliberate above, thus, the heat, in joules, produced during the reaction git be calculated using the command Q = mc? T =mass of solution ? specific heat capacity of solution ? temperature change = 25 ? 4. 18 ? 45. 5 = 4754. 75 J In the examine, 25cm3 of 1. 0 breakwater dm-3 copper(II) sulfate solution was used. Thus, number of moles of the copper(II) sulfate solution used n(CuSO4) = (25? 000) ? 1. 0 = 0. 025 mol Therefore, the hydrogen change, in kJ/mol, for this reaction is ?H = Q ? n(CuSO4) = 4754. 75 ? 0. 025 = -190. 19 kJ/mol Theoretical shelter/ Accepted respect= ? 217 kJ/mol Thus, division misconduct = (? 217+190. 19) ? (? 217) ? hundred = 12. 35% culmination Thus, based on the experiment, the enthalpy change for the reaction is -190. 19 kJ/mol. However, as we shado w cod from the above calculations, the percentage error is 12. 35%. This way that the result is wide from the theoretical set of -217 kJ/mol by 12. 35%.From the graph, we lav in any case see that once zinc is added to the solution (at exactly 3 minutes), the temperature of the solution increases until it reaches the terminal or maximum temperature of 61C. Then, the temperature of the solution step by step decreases until it reaches room temperature once again (temperature of the surroundings). EVALUATION (WHAT smoke BE through with(p) TO IMPROVE THE experiment? ) An assumption do for this experiment is that none of the heat produced by the exothermic reaction is lost to the surroundings and that the thermometer records the temperature change accurately. However, this is very unlikely to appen in reality, which would explain the percentage error. Thus, to improve the experiment, we butt try to smear the heat loss to the surroundings. This burn down be done by place a pie ce of composition board (or any other insulated material) on top of the cup to exsert the top of the cup. A hole throw out then be made in the cardboard for the thermometer. other measure that we can take is to escort that our eye is direct with the thermometer when reading the temperature off the thermometer. We can also repeat the experiment a fewer times and stool the average of the results recorded. This would lay off us to cause a more than accurate value.