英文化学报告.doc

Lab Module ReportExperiment 1Eep. Preferment week 1: 2012/10/26Preferment week 2: 2012/11/2Lab parter:Manager: Rulong WuSoftware Technician :Jean HirshfeldChemist :Sara FurgesonMethods and MaterialsPart 1: Synthesizing Sodium FerrateTo begin with, 20mL of commercial bleach was poured into a 50mL beaker, which in turn was placed with a magnetic stirring rod on a stir plate. Then 10g of NaOH pellets were added to the beaker and the stir plate turned on and the solution started to mix. Then using a pipette, 0.50mL of 0.30M FeCl was added to dissolved NaOH solution. The mixture was stirred for 10 minutes and cooled down for 5 minutes.A suction filtration apparatus was assembled and the solution was filtered so that only the concentrated solution of sodium ferrate remained.The volume of the solution was then measured using a graduated cylinder and the solution poured into a vial for later use.Part 2: Calculate the Percent Yield of FerrateThe SpectraVis spectrometer was calibrated using DI water in full spectrum mode. The DI water was removed thoroughly using a plastic pipette and the sodium ferrate was put in its place. The absorbance of the sodium ferrate at 510nm was recorded; however, since the value recorded did not meet the requirements, the solution was diluted until the value of the absorbance recorded at 510nm was beneath 1.5. When that level was reached, another sample of the solution was tested at 510nm and another value for the absorbance was recorded. The remainder of the solution was placed in another beaker in preparation for the next phase of the experiment.The concentration of ferrate in the original solution was calculated using Beer’s Law.The two values for concentration were used by taking the average of the two to get the experimental yield of the ferrate. This value of the experimental yield was compared to the theoretical yield that was calculated at the beginning of the experiment.Part 3: Performing the Reaction between Ferrate and DIatrizoicIn this part of the experiment, the goal was to perform the reaction of ferrate and DTZA to see how fast the reaction takes. The reaction was to be done two separate times and expected to be similar one to the other.In a first time, the SpectraVis spectrometer was calibrated using DI water. After the calibration the DI water was discarded in a waste beaker.Then 3mL of the sodium ferrate solution was poured into a cuvette and a measure of the absorbance at 510nm was done. Similarly to the second part, if the absorbance value was above 1.5, the solution was diluted to get an appropriate absorbance value.The cuvette was thoroughly cleaned. Afterwards, 2.0mL of DTZA at 0.040M was acquired and 1.5mL of that same solution was drawn with a pipette and poured into the cuvette.The next steps had to be done quickly in order to assure accurate results.1.5mL of the FeO42- was added to the cuvette and at that time a stopwatch was started. The absorbance was measured as soon as both solutions mixed in the cuvette. The cuvette was shaked for 5 seconds and placed in the spectrometer to measure absorbance. Every once in a while during 5 minutes worth of recording of the absorbance the cuvette was taken out and shaken. The measurements were done every 30 seconds during the 5 minute time frame. After the 5 minutes were up, the ferrate-DTZA solution was discarded in the waste beaker and the cuvette rinsed out. The above was repeated for another trial with another combination of ferrate and DTZA identical to the previous one. The work area was then cleaned and a hypothesis formulated for the research part of the experiment.Materials:· 20mL of Commercial Bleach· Stirring Bar· Stir Plate· 10g of NaOH pellets· 0.50mL of 0.30 FeCl3 solution· Suction Filtration apparatus· Graduated cylinder· Glass Vial· SpectraVis spectrometer· Pipettes· Cuvette· Waste beaker· Test tube· 0.040 M DTZA· Plastic bucket· Ice· ThermometerResults (Sara Furgeson) The theoretical yield of the reaction to create sodium ferrate using bleach, NaOH, and FeCl3 was calculated using the FeCl3 as the limiting reagent. As shown in the equation for the reaction, for every mole of FeCl3 used, one mole of sodium ferrate (Na2FeO4) would be produced.2 FeCl3 + 3 NaClO + 10 NaOH → 2 Na2FeO4 + 9 NaCl + 5 H2O The reaction used 0.50 mL of 0.30 M FeCl3, and the final amount of ferrate solution was 19mL. The theroretical yield was calculated to be 0.00769M.0.50 mL * 0.30 mol/L FeCl3 * 1L/1000mL = 0.00015mol0.00015mol / 19mL * 1000mL/L = 0.00789mol/L = 0.00789M Staring with 2.6 mL of solution, 10mL of water was added to dilute it. It’s absorbance at 510nm was 1.455, giving it a concentration of 0.M. Another sample had an absorbance of 1.192 at 510nm and a concentration of 0.M. Using the formula V1C1=V2C2 the original concentrations of the solutions were calculated to be 0.00613M and 0。