Lab Report I

Determining the Stoichiometry of chemic Reactions Mrs. Farrales Nikita Pandya October 23, 2012 December 3, 2012 INRODUCTION In the mode of persisting variations the total number of ramparts of reactants is kept unalterable for the series of measurements. Each measurement is do with a different mole dimension of reactants. A mole dimension is ratio between the get alongs in moles of any twain compounds involved in a chemic substance reply.Mole ratios atomic number 18 utilize as conversion factors between products and reactants in many chemistry problems. The optimum ratio, which is the stoichiometric ratio in the equation, form the grea running amount of product, and, if the answer is exothermic, generate the most heat and utmost temperature change, Double backup chemical reactions be primarily con nervered to be irreversible. The formation of an insoluble effect provides a driving force that makes the reaction proceed in unmatchable accusation only.In a i mage reaction, the cardinal reactants which are sedimentary dissolving agents (which place be embarrassed down), can form two products virtuoso also an aqueous solution, and other which can be a effectuate, pissing, or a gas, which cannot be broken down, thitherfore fashioning the reaction irreversible. The objective/goal of this science lab is to find the optimum mole ratio for the formation of a accrue in a double replacement reaction and use this information to predict the chemical formula of the precipitant. How can the products of a double reaction be predicted?How go out it be finalized if a product is aqueous or a precipitous? How will the method of continuous variations help determine the mole ratio of the two reactants? METHODS Materials 1. bull (II) chloride solution, CuCl2, 0. 05 M, 210 mL 2. Iron (III) treat solution, Fe(NO3) 3, 0. 1 M. 110 mL 3. Sodium hydrated oxide solution, NaOH, 0. 1 M, 320 mL 4. Sodium phosphate, tribasic, solution, Na3PO4, 0. 05 M, 210 ml 5. (14+) try on renders (some calibrated, some without graduations) 6. Black fool 7. Marking tape 8. (2) Stirring rods, life- size 9. Pipets 10. (2) turn up metro-shaped structure racks 1. (2) Pairs of gloves 12. Lab gape 13. Lab apron 14. Timer 15. space-reflection symmetry film Procedure The lab was fixed up, as it is seen in figure 1, with vii canvas renders in a render thermionic vacuum tube rack. victimization a lily-white 10mL graduated cylinder, the appropriate volume of iron(III) nitrate solution was taken from its container and transferred/added to for each one probe tube utilise a pipet. Using a another clean 10mL graduated cylinder, the appropriate volume of sodium hydroxide solution was taken from its container and transferred/added to each foot race tube, which already contained iron(III) nitrate, utilize a pipet.Before the horologe was started, each of the solutions in the run tube was stirred/mixed with a monstrous stirring rod. This ensured that both the reactants mixed properly. after(prenominal) stirring the solutions, observations were noted for any signs of chemical changes. The mixtures were to be unexpended for 10 minutes (a judgment of convictionr was used) to sit unruffled, because any consummation of the stress tube could cause a hindrance in the settlement of the f both down. though each running game tube was remaining undisturbed for 10 minutes, final observations were make after the solutions were left to sit undisturbed for 24 hours.After the 24 hours of settling, the volume of the precipitant in each test tube was measurable and preserve. For test tube with graduations, perceive the numbers at eye level made the calculations, but for test tubes with no graduations a different method was used to measure the volume of the boil down. First another test tube of the same size was found, then using a pipet, 1ml of water was measured in a 10mL graduated cylinder, and then poured into the similar size test tube. Using a black scar graduations were written on the test tube. Graduations up to 5mL only were made.After the graduations were complete the graduated test tube was held side by side with the similar size test tube with no graduations, and the precipitate was measured using this method. The same procedures were repeated with the reactants of the second table, CuCl2 and Na3PO4 foreshadow 1 The set up of the lab, the test tubes were labeled 1-7 RESULTS Data Table 1 Ratio between Fe(NO3)3 and NaOH are flummoxed in this table along with the amount of precipitate that was produced in each of the test tube. Test Tube 1 2 3 4 5 6 7 Fe(NO3)3, 0. 1M, mL 1 2 4 3 2 5 4NaOH, 0. 1M, mL 11 10 16 9 5 10 6 FeOH Mole Ratio 111 15 14 13 25 12 23 Volume of strike (mL) 1 mL 2. 8 mL 3 mL 0 mL 0 mL 0 mL 0 mL Data Table 2 Ratio between CuCl2 and Na3PO4 are presented in this table along with the amount of precipitate that was produced in each of the test tube. Test Tube 1 2 3 4 5 6 7 CuCl2, 0. 05 M, mL 1 4 4 6 6 8 5 Na3PO4, 0. 05 M, mL 5 8 6 6 4 4 1 CuPO4 Mole Ratio 15 12 23 11 32 21 51 Volume of Precipitate (mL) 1 mL 4 mL 3. 75 mL 4 mL 2. 5 mL 3. 2 mL 1 mLRESULTS PARAGRAPH POST science laboratory QUESTIONS Observations Fe(NO3)3 and NaOH 1. latch on quantify 1207 disconnected instantly. After 3 minutes disordered halfway destruction sequence 1217 Precipitate is 1/5 of test tube contort is dead orange 24 hours subsequent identical results 2. fix cartridge clip 1211 unaffectionate a trivial fetch up time 1221 The precipitate takes up 2/5 of the test tube & is orange 24 hours after alike results 3. choke time 1215 Instant dissolution give the axe time 1225 Liquid still a slim cloudy. Precipitate is ? of test tube gloss is light/dark orange 24 hours later same(p) results 4.Start time 1219 Separating VERY slowly last time 1229 there is no precipitate just yet. in truth cloudy. 24 hours later Same results 5. Start time 1222 insular ism did not find instantly annul time 1232 on that point is no precipitate just yet. genuinely cloudy. 24 hours later Same results 6. Start time 1224 insulation did not occur instantly End time 1234 thither is no precipitate. Very Cloudy. 24 hours later Same results 7. Start time 1227 Separation did not occur instantly End time 1237 There is no precipitate just yet. 24 hours later Same results CuCl2 and Na3PO4 1.Start time 1236 stranded quickly End time 1246 Precipitate ? of test tube. discolour is light blueing 24 hours later Same results 2. Start time 1237 Separated quickly End time 1247 Precipitate is ? of test tube. wile is regular blue 24 hours later Same results 3. Start time 1239 Separated quickly End time 1249 Precipitate is ? of test tube. Color is regular blue. 24 hours later Same results 4. Start time 1241 Separated only a little bit in the maiden two minutes End time 1251 Precipitate is ? of test tube and deform is light blue 24 hours later Same results 5.Star t time 1242 Separated only a little bit in the original two minutes End time 1252 Precipitate is 2/5 of test tube and falsify is light blue 24 hours later Same results 6. Start time 1243 Separated only a little bit in the offset two minutes End time 1253 Precipitate is 3/5 of test tube and color is light blue 24 hours later Same results 7. Start time 1245 Separated only a little bit in the first two minutes End time 1255 Precipitate is 1/5 of test tube and color is light blue In the observations mentioned above, estimates using numbers (fractions) were made.These fractions basically estimate the amount of precipitate that was formed in each test tube, or the lack of a precipitate. Observations were made after the ten-minute mark, and then left under the fume hood for 24hrs referable to the fact that time fell piddling observations were made then also. The observations also project that in the test tube where it was recorded that the detachment between the compounds was instan t, there was a precipitate formed. Respectively the observations also image that in test tubes where it was recorded that separation between the compounds was not instant, there was no precipitate formed.These observations describe the color of the solution/precipitate, and tell the transparency of the solution. Lastly these observations clarify on the slow or speedy process of how each solution degage into a precipitate, or didnt, based on their specific mole ratio. It justifies how the different mole ratio produced the different precipitate amount. encrypt 2 Fe(NO3)3 and NaOHFigure 3 CuCl2 and Na3PO4 These pictures show a visual of the seven test tubes in each experiment. In some of them the precipitates are present, in other test tubes there are no precipitates present, which means that they are still solutions.The test tubes with graduations, that had precipitates present were measured by reading the number at eye level. But test tube with no graduations, that had precipitat es present, a special method that was mentioned in the procedures were used. Since in experiment two, all of the test tubes had a precipitate present there was a clear preeminence in colors, the blue and clear, they were heterogonous mixtures. But in experiment one, only three of the seven test tubes had precipitates present, in those three test tubes there is a distinction in color, the red-ish orange and clear, they were heterogonous mixtures.But in the other cardinal test tubes, since they are solutions it is a unvarying mixture where the entire solution has one consistency and color. backchat By conducting the experiment, and analyzing the results, the optimum mole ratio for the formation of the precipitate in a double replacement reaction was found, and the chemical formula of the precipitate was found, the initial purpose of the experiment. At the parentage of the experiment two questions were proposed. ANSWER QUESTIONS ERRORS cultivation LITTLE BIT FROM DATA AND DISCUSS ION PARAGRAPH.