Oxidation States of Tin. Preparation of Tin (IV) Iodide

Oxidation States of Tin. Preparation of Tin (IV) IodideThe Oxidation States of Tin. Preparation of Tin (IV) iodide and Tin (II) iodide. understructureAlfred Werner, a Swedish chemist, formd the octahedral coordination of Werner multiplexes and gave rise to the field of coordination chemistry. The complexes contained a central transition metal bonded surrounded by a number of negatively or positively charged counterspycules. The coordination of the structures where unknown until Werner discovered the coordination of Hexaaminecarbon monoxide gas (II) chloride, which is written in many ways, suggesting different coordination of the atoms. The purpose of the experiment conducted is to determine the coordination of terce Werner complexes and characterize their structural formulas finished a variety of techniques. The techniques utilized are analysis of excess chlorides, measuring the conductance, magnetic susceptibility, and of hexaaminecobalt (II) chloride, pentaamine cobalt (II) c hloride, and hexaaminemickel (II) chloride.By titrating the complexes with fluid nitrate stem, a diminish of silver chloride forms and precipitates out of the solution. The non-bonding chlorides in the complexes are reacting with silver forming a precipitate with a let out solubility. By figure the amount of silver nitrate that was used in the titration, we give the gate determine the amount of silver chloride that precipitated out of solution, this results in the amount of liberal chloride in the solution. Comparing the ratios of silver chloride produced to Werner complex in the solution, free chloride ions can be determined.The conductance of complexes was also determined. The conductance of the complexes corresponds to the ions that are present within the solution. The electrical conductivity the complexes are measured once fade out in water, the anions and cations dissolve in water. This onlyows for the use of structure for metal complexes.The last technique used was t he determination of uneven electrons in the werner complexes. The Werner complexes were either diamagnetic or paramagnetic, as the contained paired or unpaired electrons which were calculated.Experimental/ObservationsPart 1 Synthesis of Hexaaminecobalt III chloride (Co(NH3)6)Cl3 In an Erlenmeyer flask, a solution containing 4.689g of cobalt III chloride (CoCl26H2O, a dark royal crystal), 3.005 g of ammonium chloride (NH4Cl, opaque yellowish crystal) and 5ml of water was heated. The solution started out purple and over time, as it was heated, a twist change was noted. Solution turned dark gamey over time. Decolorizing charcoal was added, causing the solution to become much dark. 10ml of concentrated ammonia (NH3) was added to the solution causing it to become brownish/red in color. after(prenominal) the solution was to cooled, 10ml of a 6% hydrogen peroxide (H2O2) was added, the solution was heated for 20 minutes at 600C. The solution was then cooled once again and nullity fil tered. The intelligent reddish/brown product was then transferred to a solution containing 2ml of hydrochloric acid (HCl) and 40ml of water. The filtrate was then gravity filtered and another 5ml of concentrated HCl was added. The filtrate was cooled once again and vacuumed filtered. 2.8591g of the bright reddish/brown product was dried and was isolated at a yield of 36%..Part 2 Synthesis of Pentaaminecobalt III chloride (Co(NH3)5)Cl3 7.5g of NH4Cl was dissolved in 15ml of 14M NH3. Finely ground CoCl26H2O was added the ammonia solution, in small portions, while it was agitated. The solution was initially purple and transparent and adding the the cobalt crystals resulted in the physical composition of a brown slurry. 7.5 ml of 30% H2O2 was slowly added to the brown slurry, causing an hunch overervescence reaction to occur, releasing a white gas and becoming much darker. at a time the effervescence had subsided 45ml of HCl was added to the solution. The solution was heated to 850C and agitated for 20 minutes, then cooled down as a two layered solution was formed. A top unforgiving layer and a bottom dull pink layer. The precipitate was then vacuum filtered and washed with 30 ml of ice cold water, 6M HCl, and 100% ethanol. 6.5729g of the purple product was dried and isolated with a yield of 80%.Part 3 Synthesis of hexaaminenickel III chloride (Ni(NH3)6)Cl2 1.2g of hydrated NiCl2, a fine light super acid powder, was dissolved in 95% ethanol. 5ml of 14M NH3 was added to the nickel solution as it was brought to a boil. The addition of the ammonia lead to the formation of a faint purple precipitate that was vacuum filtered and wash with ethanol. 0.58g was isolated with a % yield. abbreviation of CompoundsThe products were analyzed to determine their magnetic susceptibility, conductance and the amount of free chloride in solution. The conductance measurements were obtained for all lead products through the Sherwood scientific apparatus. 50 ml of 110-3 M aqueous solution of each of the products was prepared by dissolving 0.01570g of Ni(NH3)6Cl2, 0.01252 g of Co(NH3)6)Cl3 and 0.01337g of Co(NH3)5)Cl3 in a 50 ml volumetric flask. The conductance measure was then taken.A Johnson-Matthey magnetic susceptibility balance was used to determine the magnetic jiffy of each of the three products. The products were packed into a furnish and the reading was taken.The analysis of free chlorides was carried out on both cobalt solutions. 0.05g of the cobalt products was dissolved in a 50ml Erlenmeyer flask and titrated with silver nitrate solution. fluorescent dye was used as an indicator and the end point was determined to be a bright pink layer of the cobalt solution.DataTable 1. Results for the synthesis of Co(NH3)6)Cl3, Co(NH3)5)Cl3 and Ni(NH3)6)Cl2Actual yieldPercent yield ATheoretical yield B(Co(NH3)6) Cl32.8591g54.2%5.272g(Co(NH3)5)Cl36.5729g83.29%7.891g(Ni(NH3)6)Cl20.58g49.23%1.170gSample calculation for percent and theoretical yeild of Co(NH 3)6) Cl3 Table 2. Results for the analysis of free chlorides for (Co(NH3)6)Cl3 and (Co(NH3)5)Cl3Volume of AgNO3Mass of compoundMoles of free Cl-(Co(NH3)6)Cl30.532 ml0.514ml0.05g3(CO(NH3)5)Cl30.417ml0.515ml0.05g2Sample calculation for moles of free cholride for Co(NH3)6) Cl3 Table 3. Results for Conductance Measurements for three compoundsMolar conductance (ohm-1cm2mole-1)Number of ions CLit. ValuesC (ohm-1cm2mole-1)Co(NH3)6Cl3297.64235 273Co(NH3)5Cl3100.82118 135Ni(NH3)6)Cl2234.33235 273 C) Values obtained from appendix from corresponding molar conductance values.Table 4. Results for the magnetic susceptibility for the three compoundsg (emu mol-1)MeasDiaParaeffSUnpaired electrons(Co(NH3)5) Cl3-3.046*10-8-3.25*10-6-190.2 * 10-60.00018640.66250.2350(Co(NH3)6)Cl3-2.603*10-8-6.507*10-6-177.2*10-60.00017060.63260.22360(Ni(NH3)6)Cl2-1.015*10-7-2.345*10-5-166.7*10-60.00007130.0200.0100Sample calculation for (Co(NH3)5) Cl3 Chemical EquationsIn the three-chemical reactions, the metals re acted with the amine forming the products. The chemical reactions are as followsPart 1 2CoCl26H2O(s) + 2NH4Cl+10NH3(aq) + H2O2(aq) + 3H2O(l) 2Co(NH3)6Cl3 + 1/2O2(g)Part 2 2CoCl26H2O(s) + 2NH4Cl+8NH3(aq) + H2O2(aq) + 3H2O(l) 2Co(NH3)5Cl3 + 1/2O2(g)Part 3 NiCl26H2O(s) + 6NH3(aq) Ni(NH3)6Cl2(s) + 6H2O(l)An oxidation reduction reaction was occurring as hydrogen peroxide was added to the cobalt solutions and used to melt off the cobalt to its 2+ assert. The redox reaction is as followsR H2O2 H3O+ + 1/2O2 + e (1)O Co3+ + e Co2+ (2)DiscussionTo determine the structure of the three complexes, three different techniques where utilized. A magnetic subspecialty measurement, a conductance measurement, and an analysis of free chlorides in each of the three products. Visible color changes were observed in the formation of the brightly colored products indicating that a successful reaction had occurred. The change of color is due to the change in oxidation state. Hydrogen peroxide was used in the reduction of cobalt complexes producing two differently colored cobalt complexes. The in the oxidation reaction we see a change in oxidation state of Co from 3+ to 2+ as hydrogen peroxide is being oxidized. A change in oxidation state causes the solution to change color as the metal complexes contain electrons that absorb light energy and jump to an excited state in a different molecular orbitalAnalysis of free chloride. A solution containing 0.05g of Co(NH3)6Cl3 and Co(NH3)5Cl3 was titrated with a silver nitrate solution. The number of moles of free chloride ions was then calculated through their mole ratios. It was determined that Co(NH3)6Cl3 solution contained3 free chloride ions while (Co(NH3)5Cl3 solution contained 2 free chloride ions. The calculated ratios (Table 2) of free chloride ions indicates whether the Chlorine ions are bonded with the cobalt complex, as free chloride ions will precipitate out of the solution in the presence of silver nitrate. From this we can assume that 2 moles of chlorine are not bonded to in cobalt complex in Co(NH3)5) Cl3 while all 3 moles of chlorine are not bonded to the cobalt complex in Co(NH3)6)Cl3. We can conclude that chlorine helps stabilize the positive charge of cobalt complex in Co(NH3)6)Cl3 while a single chloride ions is bonded to the cobalt complex of Co(NH3)5Cl3. Fluorescing, the indicator used in the titration, was added to the solution with 2ml of 2% dextrin solution. The dextrin solution prevents the coagulation of AgCl and the prevention of the AgCl amount of money on the surface of the solution.Molar conductance. A solution of all three products was prepared with a concentration of 10-3M. The molar conductance reading was then taken at 20.50C on a Sherwood scientific apparatus. The conductance values were obtained and compared to the publications values and the number ions of each solution can be determined. Co(NH3)6Cl6 had a conductance value of 297.6 ohm-1cm2mole-1. From the corresponding lite rature value, this conductance is due the presence of 4 ions in one mole solution. Similarly, Co(NH3)5Cl5 and Ni(NH3)6Cl2 had molar conductance value of 100.8 and 234.3 ohm-1cm2mole-1 which correspond to 2 and 3 ions per mole of solution respectively. From this we can determine the formula of each of the compounds. In hexaaminecobalt (III) chloride, 4 total ions are present which results in one from Co(NH3)62+ + 3Cl. In pentaaminecobalt (III) chloride, 2 ions are present, one from Co(NH3)52+ + Cl. In pentaaminenickel (II) chloride, 3 total ions are present, one from Ni(NH3)52+ + 2Cl. However, for data from the analysis of free chloride does not confer with the molar conductivity of the pentaaminecobalt (II) chloride complex. From the analysis of free chlorides, it was determined that one mole of the complex contained 2Cl while the molar conductance suggest 2moles of chloride ion. This discrepancy whitethorn be due to the product not being fully dried, and the moisture water may inte ract and distort the reading of conductance.Magnetic Susceptibility. The magnetic susceptibility was carried out on a Johnson-Matthey apparatus that determines the magnetic moment of each complex. Through calculating Spin values it was determined that both Cobalt (Co3+) complexes, with a d6 electron configuration, does not have any unpaired electrons as the offer values were abutting to 0. From this, we can assume that the electrons are in a low spin state as Hunds rule of multiplicity suggest that electrons would be paired with altering spin states, and unpairing the electrons would require an increase in energy to overcome 0. The Nickel (Ni2+) complex contain two unpaired electrons. Its d8 electron configuration, with 2 unpaired electrons in a high spin state. The low spin state would not be observed as paring the two electrons was require extra energy.The three compounds, (Co(NH3)6) Cl3, (Co(NH3)5)Cl3, (Ni(NH3)6)Cl2 were successfully produced and to give yields of 54.2%, 83.29 %and 49.23% respectively for the three compounds.The yields of (Co(NH3)6) Cl3 and (Ni(NH3)6)Cl2 is rather low but it to be expected as the sample may have been lost during the vacuum filtration process while being transferred. The coordination of the three complexes was determined to be Co(NH3)6Cl3, Co(NH3)5Cl)Cl2 and Ni(NH3)5Cl2.ConclusionThe purpose of the experiment was to characterize the structural formulas werener complexes through the synthesis of Co(NH3)6Cl3, Co(NH3)5)Cl3 and Ni(NH3)5Cl2 and the coordination of the compounds was determined to be Co(NH3)6Cl3, Co(NH3)5Cl)Cl2 and Ni(NH3)5Cl2 . The characterizations were conducted with three techniques that determined the moles of free chloride ions, conductance and magnetic moment of the three complexes. The analysis of free chloride ions determined that 3 and 2 chloride ions were present per mole of the two cobalt complexes. Indicating that Cl is bonded to Co(NH3)62+ complexes, while non-bonded to the Co(NH3)5, but function to stabilize the charge on the complex. The molar conductance of the complexes resulted in the presence of 4,2 and 3 total ions for the three Werner complexes. Lastly, the magnetic moment of three complexes was determined and the spin states where calculated. It was determined that both cobalt complexes (Co3+) contained 0 unpaired electrons, in a d6 diamagnetic electron configuration, in a low spin state. The nickel complex was found to contain 2 unpaired electrons, in a d8 paramagnetic electron configuration, with 2 electrons in the high spin state.ReferencesSimon Fraser University. Inorganic Chemistry, Chemistry 236W laboratory manual 2016. Vol. 1.81. Print. 9 -10Miessler, G. L. Tarr, D. A. Inorganic chemistry Prentice Hall Boston, 2011.