Determining Activation Energy

Activation energy of a reply Mengyuan Wu IB Chem HL Richard Forster March 20, 2013 Introduction In this experiment, a reduction of peroxodisulphate (VI) ions by iodine ions is investigated. source of 10cm3 of K2S2O8, potassium peroxodisulphate, represented as Solution A. mixture of 5cm3 of KI (Potassium iodide solution), and 5 cm3 of Na2S2O3 (sodium thiosulphate solution), and 2. 5cm3 of starch solution is considered as Solution B.Solution A and B are heterogeneous together under distinct temperatures to show a clock reaction. Observation shelve 1 in the raw Quantitative selective information of Temperature and prison term from the investigate refractory / Ideal Temperature (C) Temperature of Solution A (C0. 5C) Temperature of Solution B (C0. 5C) Time Taken Time Proceeded (seconds1 seconds) 30 31. 0 31. 0 31034 191 35 36. 0 33. 5 21183 132 40 40. 0 38. 0 13724 97 45 46. 0 45. 5 11283 73 50 51. 0 51. 0 05240 53 QualitativeBefore Solution A acquit food colouringless soluti ons Solution B clear contortless solution During both(prenominal) solution A and B reached (or close to) a fixed temperature and mixed together form a clear colorless solution reaction time one or few section of the solution cancelled clear light purpleness opaque purple, then the section lard to the entire solution speedily within a second the purple opaque solution gradually turn to a darker purple color After Dark purple-black colored opaque solution puzzle outing and Presenting Data plug-in 2 Uncertainty of the Apparatus Used in the Experiment Equipment Uncertainty Explanation Stopwatch Seconds1 second The actual unbelief of the stopwatch is millisecond, shown in the column Time Taken in flurry 1. However, there are human reaction uncertainties when receiving the change in color in the actual experiment, so that particular uncertainty is presented by 1 second 50cm3 Burette for K2S2O8, KI, and Na2S2O3 cm30. 02cm30. 02% for each solution Initial Reading (0. 1cm3) + nett re ading (0. 1cm3) = volume used (0. cm3) for every solution measured in mixture A or B 10mL Measuring Cylinder for starch solution mL0. 2mL Thermometer C1. 0C Mixture A and B both have separate (but relatively close) temperature with uncertainty of 0. 5C each, after the average of the two the uncertainty doubles Table 3 Processed date for temperature and time Average Temperature of the reaction (C1. 0C) Proceed Temperature (K1. 0K) Time Proceeded (seconds1 seconds) 31. 0 304. 0 191 35. 0 308. 0 132 39. 0 312. 0 97 46. 0 319. 0 73 51. 0 324. 0 53Table 4 Processed entropy for interpreting ln 1t (3 sig fig) 1T (K)(4 sig fig) -5. 25 0. 003289 -4. 88 0. 003246 -4. 57 0. 003205 -4. 29 0. 003134 -3. 97 0. 003086 ln 1t=lnK (Proportional) t= Time T= Temperature (in K) Graph1 weighing Values Table 4 calculation to Process Temperature deliberateness 1 Average Temperature (C1. 0C) Calculation 2 Temperature in K (K1. 0K) Formula Temp. of A+Temp. of B2 Temp. in C+273 Fixed / Ideal Temperat ure (C) 30 31. 0+31. 02=31. 0 31. 0+273=304. 0 35 36. 0+33. 52=34. 75? 35. 0 35. +273=308. 0 40 40. 0+38. 02=39. 0 39. 0+273=312. 0 45 46. 0+45. 52=45. 75? 46. 0 46. 0+273=319. 0 50 51. 0+51. 02=51. 0 51. 0+273=324. 0 Table 5 Calculation for Graphing Data Calculation 3ln 1t Calculation 41T(K) Fixed / Ideal Temperature (C) 30 ln1191? -5. 25 1304? 0. 003289 35 ln1132? -4. 88 1308? 0. 003246 40 ln197? -4. 57 1312? 0. 003205 45 ln173? -4. 29 1319? 0. 003134 50 ln153? -3. 97 1324? 0. 003086 Calculation 5 (Activation Energy) lnk= -EaR ? 1T+lnA y = m(slope) x + c R=8. 314 Jmol-1K-1(Diploma)Data from Graph 1 y = -6045. 3x + 14. 705 -6045. 3 = -EaR Ea=8. 314 ? 6045. 3 =50260. 6242 J =50. 2606242 KJ haphazard mistakes Calculation 6 (%Random Error for Average Temperature of the Reaction) Average temperature of the reaction K 1. 0 K (Refer to Table 2) % Error=1. 0304. 0+1. 0308. 0+1. 0312. 0+1. 0319. 0+1. 0324. 0? 100 ? 1. 596% Calculation 7 (%Random Error for Time) Time Taken Secon ds 1 Second (estimated human reaction time) (Refer to Table 2) % Error=1191+1132+197+173+153? 100? 5. 569% Calculation 8 (% Random Error for Solutions) Random Error for K2S2O8+KI+ Na2S2O3+Starch 0. 02%? 3+0. 22. 5? 100 ? 8. 06% Calculation 8 (Total % Random Error) % Error=1. 596%+5. 569%+8. 06% =15. 225%=20% (one sig. fig. ) Final Answer Calculation 9 (Final Answer) 50. 2606242 KJ 20% 50. 2606242 KJ =50. 3 KJ (3 sig. fig. smallest sig. fig. in calculation) 50. 2606242 KJ? 0. 2? 10. 052 KJ=10KJ (one sig. fig. ) Experimental solution 50. 3 KJ 10KJ 50. 3 KJ 20% Work Cited Diploma Programme chemistry Data Booklet. 2nd ed. Cardiff International Baccalaureate Organization, 2008. 6. Print.