Experiment 2Experiment Date: 02/09/17Chem 322L-002MFan WangPurposeThe goal of this experiment was to determine the amount of calcium in a sample of calcium carbonate via gravimetric analysis. Essentially the goal was to determine the calcium composition of an impure sample of calcium carbonate (CaCO3(s)) by converting the calcium ion into calcium oxalate monohydrate (CaC2O4.H2O) and using homogeneous precipitation to crystallize the product. The mass results for the calcium recovered were analyzed by calculation of molarity of Ca in the solution, weight percent of Ca in solid sample, and standard deviation.ExperimentalTo begin the experiment, three oven dried crucibles were allowed to cool in a desiccator while 1 g of an unknown calcium carbonate sample were dissolved in 5mL of concentrated HCl, then thesolution was diluted with deionized water up to 50mL. The solution was filtered and then, three 5mL aliquots of the solution were transferred via volumetric pipet to three separate 50mL Erlenmeyer flasks. Each of these beakers was rinsed three times with 0.1 M HCl solution prepared by TA and then the rinse solution was added to the same Erlenmeyer flask. This was repeated twice, to prepare a total of three 50 mL Erlenmeyer flasks with approximately 20 mL of solution in each one. This was followed by the addition of 10mL of ammonium oxalate to each of the samples. Finally, approximately 6g of urea was added to each solution and they were allowed to boil for 30 minutes. The crucibles were then removed from the desiccator and fitted to filter flasks. Each solution was poured through a separate crucible, dried via aspirator. Finally, the crucibles were allowed to cool for 10-15min and weighed to determine the amount ofcalcium precipitate. Note: during the experiment, much of the product flowed through the crucible and was lost with the discarded solution. Results are expected to be lower than the true value.Calculations:Molarity=0.0142930.05=0.285851Weight %=0.5728170.996200∗100 %=57.500219 %Density=0.9962000.05=19.924Mean=0.285851+0.283907+0.2831953=0.284318Spooled=√(15−1)(2.3400662)+(18−1)(21.1619592)15+18−2=15.75Texp=11.26519−2.48587615.75×√(15) (18)15+18=1.594Results:Table 1. Group Tums DataTumsSample B(g)DensitySolution1 (g/L)Grams in5mLDensitySolution2 (g/L)Grams UreaCrucibleweight(nosample)CrucibleweightwithsampleGramsCaC2O4·H2OCa2+ % inCaC2O4·H2OGramCa 2+MolesCa2+MolarityCa 2+Weight %0.998 19.964 0.099 1.996 6.009 31.070 33.158 2.088 0.274 0.572 0.0149 0.285 57.3850.099 1.996 6.049 30.802 32.876 2.073 0.274 0.568 0.0141 0.283 56.9940.099 1.996 6.053 30.811 32.880 2.068 0.274 0.567 0.0141 0.283 56.851Average 0.284 57.07Standard Deviation 0.0013 0.27695% CI 0.0034 0.685Degrees of Freedom 3 3Table 2. Class Tums DataInitial massofunknownsample (g)DensitySolution 1(Mass/0.5)Grams in5mL(Density/0.005)DensitySolution 2(g/L)GramsCaC2O4·H2OCa2+ % inCaC2O4·H2OGram Ca 2+(gCaC2O4/Ca2+%)Moles Ca2+(G/40.078)Molarity Ca 2+(Moles/.05)Weight %(G Ca2+/mass)*1000.99620019.924000 0.09962 1.9924002.088100 0.274325 0.572817 0.014293 0.285851 57.5002190.996200 2.073900 0.274325 0.568922 0.014195 0.283907 57.1091920.996200 2.068700 0.274325 0.567495 0.014160 0.283195 56.9659991.00370020.074000 0.10037 2.0074000.101600 0.274325 0.027871 0.000695 0.013909 2.7768631.003700 0.098900 0.274325 0.027131 0.000677 0.013539 2.7030691.003700 0.207200 0.274325 0.056840 0.001418 0.028365 5.6630521.05000021.000000 0.10500 2.1000000.085000 0.274325 0.023318 0.000582 0.011636 2.2207231.050000 0.037800 0.274325 0.010369 0.000259 0.005175 0.9875691.050000 0.027600 0.274325 0.007571 0.000189 0.003778 0.7210821.01300020.260000 0.10130 2.0260000.058000 0.274325 0.015911 0.000397 0.007940 1.5706641.013000 0.061000 0.274325 0.016734 0.000418 0.008351 1.6519051.013000 0.066000 0.274325 0.018105 0.000452 0.009035 1.7873071.00510020.102000 0.10051 2.0102000.066800 0.274325 0.018325 0.000457 0.009145 1.8231901.005100 0.100800 0.274325 0.027652 0.000690 0.013799 2.7511611.005100 0.085600 0.274325 0.023482 0.000586 0.011718 2.3363031.00360020.072000 0.10036 2.0072000.042200 0.274325 0.011576 0.000289 0.005777 1.1534971.003600 0.051300 0.274325 0.014073 0.000351 0.007023 1.4022371.003600 0.059900 0.274325 0.016432 0.000410 0.008200 1.637310Average 0.056130 11.264519Standard Deviation 0.105143 21.16195995% CI 0.053158 10.699092Degrees of Freedom 17 17Table 3. Class CVS DataGroup Data vs. Class Data Tums vs. CVSWeight % Molarity Weight % MolaritySpooled20.02 0.09945 15.74 0.07825ttable1.746 1.746 2.101 2.101texp3.670 3.679 1.594 1.596Table 4. Pooled Standard Deviation and T-TestsInitial massof unknownsample (g)DensitySolution 1(Mass/0.5)Grams in5mL(Density/0.005)DensitySolution2 (g/L)GramsCaC2O4·H2OCa2+ % inCaC2O4·H2OGram Ca 2+(gCaC2O4/Ca2+%)Moles Ca2+(G/40.078)Molarity Ca2+(Moles/.05)Weight % (G Ca2+/mass)*1001.01220020.244000 0.101220 2.0244000.062600 0.274325 0.017173 0.000428 0.008570 1.6965741.012200 0.053000 0.274325 0.014539 0.000363 0.007255 1.4363961.012200 0.133200 0.274325 0.036540 0.000912 0.018234 3.6099621.00630020.126000 0.100630 2.0126000.064200 0.274325 0.017612 0.000439 0.008789 1.7501381.006300 0.055500 0.274325 0.015225 0.000380 0.007598 1.5129701.006300 0.061600 0.274325 0.016898 0.000422 0.008433 1.6792601.00300020.060000 0.100300 2.0060000.053500 0.274325 0.014676 0.000366 0.007324 1.4632471.003000 0.059000 0.274325 0.016185 0.000404 0.008077 1.6136741.003000 0.059100 0.274325 0.016213 0.000405 0.008091 1.6164091.00420020.084000 0.100420 2.0084000.072900 0.274325 0.019998 0.000499 0.009980 1.9914621.004200 0.043200 0.274325 0.011851 0.000296 0.005914 1.1801261.004200 0.042000 0.274325 0.011522 0.000287 0.005750 1.1473441.00020020.004000 0.100020 2.0004000.251100 0.274325 0.068883 0.001719 0.034374 6.8869131.000200 0.025100 0.274325 0.006886 0.000172 0.003436 0.6884171.000200 0.328700 0.274325 0.090170 0.002250 0.044998 9.015246Average 0.012455 2.485876Standard Deviation 0.011674 2.34006695% CI 0.006360 1.274867Degrees of Freedom 14 14DiscussionNot as predicted, the results for the mass of calcium precipitate were much higher than predicted. As seen from the mass percentages, there was an exceptional amount of product remaining in each crucible compared to the data of the class. This cause of the huge difference might have come from inaccurate drying methods leading to a wet product being weighed out. With this gross error, the results are not consistent, seen by the