Final Lab Report Sample

Date Performed July 30, 2012 EXPERIMENT NO. 10 COMPOSITION OF POTASSIUM CHLORIDE ABSTRACT The presence of the audition was to look for the serving formation of the elements present in the de study of h iodiny oil chlorate (KClO3) and to find out what the ease aft(prenominal)ward heat was. After performing the investigate the researchers instal out that there were about(predicate) 66. 14% of kB chloride (KCl) in KClO3, and they to a fault deducted that the respite was actually KCl. _____________________________________________________________________________________Introduction aggregate view of the Element/ composite (Part) agree push-down store of Compound (Whole) ? vitamin C The facial expression above is the formula utilise to determine the partage motif of an individual element in a deepen. In this experiment, the researchers be both pass to solve for the metaphysical per centumage musical composition and the experimental parting composition of elemen ts/ ions. The theoretical portion composition is work out use a known formula compound and an experimental share composition is solved using data identified in the experiment.The goal of this experiment is to formulate a diminutive percentage misplay as possible, which is solved using the formula below. metaphysical value-Experimental valueTheoretical value ? degree centigrade The compound that they are going to use in this experiment is KCl or potassium chlorate. Potassium chlorate, when change to postgraduate temperatures would form this equation 2KClO? (s) ? 2KCl (s)+3O? (g) influence The experiment was composed of two antitheticiates. The prototypic choose around was for determining the percentage composition of potassium chlorate.First, the researchers made sure that the melting pot, which would be used throughout the experiment, was dry, so they alter it on a dust trigon for 2-3 minutes. Next, they let the melting pot cool follow out a second gear and thu sly weighed it in concert with its top of the inning. Then they added 1. 196 g of potassium chlorate into the crucible, pose its lid and then weighed it. After that, they modify the crucible again on the clay triangle for 8 minutes with its cigarette 2. 5-3 inches away from the flame. They heated it for another 10 minutes, that time adding a little bit of distance between the flame and crucible bottom.They allowed the crucible to cool for about 10 minutes. Then they reweighed the example for 6 to a greater extent minutes, cooled it and then weighed it again. In the second fate of the experiment, they took 3 test tubes, one containing a small amount of potassium chloride, one with a like amount of potassium chlorate, and one that contained a solution obtained from adding distilled urine to the crucible, that was used in the first break down of the experiment, and heated it for about a minute, and then they added 10 ml of distilled water to to each one and stir.In each of the tubes, they added 5 drops of dilute (6 M) nitrous acid and 5 drops of 0. 1 M smooth-spoken nitrate solution, then stirred each test tube and dis even offed carefully. Results and Discussion On the first part of the experiment, the researchers started off with the crucible with the adjudicate that weighed 37. 184 g. , aft(prenominal)ward the first change, the portion decreased and became 37. 093 g. , after the second heating, the mass decreased again and became 36. 787 g. , the difference between the two wasnt less than 0. 05 g. , so they had to reheat.After the third heating, the incubus became 36. 779 g. , their difference was within 0. 05 g. so no more heating is required. After calculating, the researchers represent out that the theoretical percentage of type O in KClO3 is 39. 17% and that the experimental percentage of group O they got in KClO3 was 33. 86%. On the other hand they also found out that theoretical percentage of KCl in KClO3 is 60. 83% and that their experimental percentage of KCl in KClO3 was 66. 14%. and that the experimental attempt to get the percentage of group O in KClO3 had an error of 8. 3%. On the second part of the experiment when 5 drops of dilute (6 M) nitrous acid and 5 drops of (0. 1 M) silver nitrate solution were added to the solution of the residue and distilled water, potassium chloride solution, and potassium chlorate solution, all of them morose cloudy with white precipitate in them which indicated that chloride ions were present which lead to the deduction that the residue was actually KCl. 1. great deal of crucible + spinal column 35. 988g. 2. mountain of crucible + cover + sample before heating 37. 84 g. 3. Mass of crucible + cover + residue after 1st heating 37. 093 g. 4. Mass of crucible + cover + residue after second heating 36. 787 g. 5. Mass of crucible + cover + residue after 3rd heating 36. 779 g. 6. Mass of authorized sample=37. 184? 35. 988=1. 196 1. 196 g. 7. Total mass lost during h eating=37. 184? 36. 779=0. 405 0. 405 g. 8. last-place mass of residue=1. 196? 0. 405=0. 791 0. 791 g. 9. Experimental percent oxygen in KClO3=0. 4051. 196? ampere-second=0. 3386? carbon=33. 86% 33. 6% 10. Experimental percent KCl in KClO3=0. 7911. 196? c=0. 6614? degree Celsius=66. 14% 66. 14% 11. Theoretical percent oxygen in KClO3=3(16. 00)39. 10+35. 45+3(16. 00)? 100=48122. 55? 100=0. 3917? 100=39. 17% 39. 17% 12. Theoretical percent KCl in KClO3=39. 10+35. 4539. 10+35. 45+3(16. 00)? 100=74. 55122. 55? 100=0. 6083? 100=60. 83% 60. 83% 13. pct error in experimental % oxygen determination=60. 83-66. 1460. 83? 100=-5. 3160. 83? 100=-0. 0873? 100=8. 73% 8. 73% Conclusion and RecommendationAs seen above, the experimental percent gotten by the researchers wasnt that furthermost off from the theoretical value, and they ended up with a percent error of 8. 73%. Thats not a high percent error, but in chemistry, where truth is very vital, that amount is already considered high. u nity of the factors that led them to a high percentage error was that they used a different balance for the weighing of 4 and 5 in the table. For further experimentation, the researchers suggest that sole(prenominal) one balance would be used throughout the experiment.It is also important to concord the crucible steady so that dot wont happen during heating. Because when splattering does happen, mass lost would no long-term be accurate. References * Book Hein, MORRIS, et al. , FOUNDATIONS OF CHEMISTRY IN THE LABORATORY FOR SCIENCES (CUSTOM EDITION), 12th ed. , Singapore129809, 2009 Appendix 1. Mass of certain sample= (mass of the crucible + cover + sample before heating) (mass of crucible + cover) 2. Total mass lost during heating= (mass of the crucible + cover + sample before heating) (mass of the crucible + cover + after 3rd heating) 3.Final mass of residue= mass of original sample total mass lost during heating 4. Experimental percent oxygen in KClO3=total mass lost durin g heatingmass of original sample? 100 5. Experimental percent KCl in KClO3=final mass of residuemass of original sample? 100 6. Theoretical percent oxygen in KClO3= submarine mass of O? molar mass of KClO 100 7. Theoretical percent KCl in KClO3=molar mass of KClmolar mass of KClO 100 8. Percent error in experimental % oxygen determination=theoretical value-experimental valuetheoretical value? 100