Answer Happy

The Experiment Your team should first consider the reagents and reagent quantities needed to understand the reactions needed to produce alum. AAR recommends that you first determine a way of dissolving the aluminum cans. You may need to use a slight excess of reagent in order to completely dissolve the sample in a reasonable time period. AAR also has pointed out that the cans will still be painted and have their inner coating. Your team should consider these facts as you plan the reaction - you likely do not want these materials in your reaction vessel. AAR will be paying for all disposal costs as part of this project - and disposal of these reagents Lab5 is currently very expensive. Thus, AAR has instructed your team to only use approximately 1.25 g samples of aluminum for each experiment.
is currently very expensive. Thus, AAR has instructed your team to only use approximately 1.25 g samples of aluminum for each experiment. AAR has sent along the following reactions so that you may plan for each step of the synthesis. In general, gently heating this mixture will greatly speed up the reaction. Step 1: 2 Al(s) + 2 KOH(aq) + 6H2O(1) ► 2K+(aq) + 2 Al(OH)2(aq) + 3 H2(9) KOH will dissolve human tissue. Sulfuric acid is next added to the cooled product mixture of reaction 1. Step 2: 2 Al(OH)2 (aq) + H2SO4(aq) + 2 Al(OH)3 (s) + so (aq) + 2 H20(1) 9 M sulfuric acid is a strong, caustic acid that will burn skin. Excess sulfuric acid dissolves the solid aluminum hydroxide Step 3:2 AIOH3 (s) + 3 H2SO4(aq) + 2 A13+ (aq) + 3 504 (aq) + 6 H20(1) The mixture is then cooled and alum is formed. Step 4: Al3+ (aq) +K+ (aq) + 2 s02-(aq) + 12 H20(1) ► KAl(SO4)2 • 12 H20(s)
Keep in mind that stirring the final mixture can prevent crystal formation. Alum should present as readily observed crystals. If the glassware you are using is rather new you can lightly scratch the inside of the vessel with a glass rod. This will help crystal formation. AAR does state that if you added too much excess sulfuric acid alum may crystallize. Once you have crystallized your alum it should be isolated and dried using suction filtration. Washing your product will remove any unwanted or unreacted chemicals, but you must not use a wash solvent that dissolves alum. AAR recommends trying a 1:1 mixture of ethanol and water to wash the alum crystals. Also, the wash solvent should be cold. Once you have isolated your dried alum you need to calculate a percent yield. AAR needs you to perform at least two syntheses, with a third being optional. You should observe a larger percent yield on your second synthesis. Report Your team will assemble a typed and grammatically correct report and submit it to AAR. AAR requires that you outline, in detail, your procedures. All calculations must be shown as well as any chemical equations. AAR will also need a complete cost analysis - you can find detailed costs for all of the chemicals and labware used on the internet. Also include standard labor costs accrued by your team. Lastly, provide AAR with a cost to scale this procedure to 100 kg. Again, consider internet sources to complete a cost analysis and cite any sources used in your analysis.