RESULTS AND DISCUSSION In the Iron (II) – Silver Ions System the reaction had a balance chemical equation of Fe2+ + Ag+ ?? Fe3+ + Ag(S). The process if centrifugation is used in this part of the experiment to be able to separate the supernatant and the precipitate. And the supernatant will be used to test for the presence of Fe2+, Ag+ and Fe3+ in the solution. Results showed that there is a positive presence for FE 2+, Fe3+ and Ag+ because of the visible change of color of Prussian blue precipitate, blood red solution and white precipitate. The balance chemical equation for the reactions were Fe2+ + K3Fe(CN)6 ? ? Fe(CN)36 +K2 +Fe , Fe3+ + KCSN ?? Fe(SCN)3+K and Ag+ + HCI ?? AgCl + H+. The bonding between the ions in the solution is weak because it can be separated easily and they are very reactive to the solution used as the test reagents since the range of the Keq for this reaction is greater than 102 , a forward reaction that is highly favored with the formation of product. In addition HCl the solution formed white precipitate. Because HCl is responsible for the precipitate being dissolve and it also decolorizes the solution because in the chemical equilibrium it shifts forward to the product’s side of Ag+ + HCI ??
AgCl + H+ producing more product. In the copper-ammonia system the balance chemical equation is [Cu(H2O)6]2+(aq) + 4NH3(aq) ? [Cu(NH3)4(H2O)2)]2+(aq) + 4H2O(l) and the initial color was pale blue and when 8 drops of NH3 was added to the solution the color changed to dark blue having the chemical equilibrium have a forward reaction while for the addition of 9 drops of HCl the color went back to pale blue and the equilibrium shifted back to the reactant side.
In the chromate-dichromate system results showed that chromate solution have yellow color while for dichromate have orange color and when base is added chromate remained yellow but the dichromate from orange to yellow. And when an acid was added chromate turned orange while dichromate remained orange. The acid solution used was H2SO4 because it is highly acidic. 2CrO4-2(aq) + 2H3O+(aq) ? 3H2O(L) + Cr2O7-2(aq) is the balance chemical equation of the system. When the acid solution is added the equilibrium shifts to the left making the solution orange and when basic solution is added to the solution he equilibrium shifts to the right making the solution yellow. Therefore, chromate is the stable as base and dichromate is stable as acid. In the Iron Thiocyanate Equilibrium has the balance chemical equation of Fe3+(aq) + 6KSCN(aq) ——> [Fe(SCN)6]3-(aq). After the addition of Fe3+ the solution became dark orange which means that the equilibrium shifted to the left, when SCN- was added the solution became a more intense orange than the color in Fe3+ which also means that the equilibrium to the right, and lastly when NaCl was added the solution became pale yellow which means that the equilibrium shifted to the left.
In the cobalt (II) ions system has the balanced chemical equation of Co(H2O)62+(pink) + 4Cl– + heat?? CoCl42– (Blue)+ 6H2O. At a room temperature the solution remained pink and after heating the solution became blue. The system is an exothermic reaction and it was explained by the excess addition of heat will shift the equilibrium to the right making the solution blue. CONCLUSION AND RECOMMENDATION In summary the factors that affect the equilibrium or the shifts of the reaction to forward and backward are the volume, pressure and temperature.
When the volume decreases the pressure increases and the increase in pressure favors the reactant side or the equilibrium shifts to the reactant side because it has lesser moles while for temperature, if the system is exothermic adding heat will favor the forward reaction like in cobalt (II) system and for endothermic adding heat favors the reverse reaction. To be able to gather successful results one should follow the instructions comprehensively like adding the correct concentrations of the solutions and having the apparatus clean will avoid contamination for the results. Using different transfer apparatus for every reagent is important.
