User:Mobeen Ashraf/Notebook/Chem-581/2012/09/19

Experimental Chemistry

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Objective Part I) Acid Catalytic Dehydration reaction in cross-linking of glutaraldehyde. Part II) solubility tests of the resultant film, swelling studies and neutralization of films in sodium carbonate solution. Part III) Make 2nd glutaraldehyde film, except replace 20% of PVOH with PDMS. Part IV) Prepare 1L of glutaraldehyde fixed solution. Part (V) Prepare 500 ml of 20 ppm sulfate as CuSO4 and Na2SO4. Part (VI) Filter the clays from 09/12/12. Description Part I In a 100 ml of water solution, 20 g of sodium sulfate was placed. Once the solution was dissolved, 2 ml of the concentrated sulfuric acid was added. The resultant mixture was allowed to reach at the temperature of 70 deg Celsius before adding 0.1 g of PVOH having the molar mass of 22,000 cross-linked with glutaraldehyde film. When 1 hour was elapsed, the film was taken out of the solution and was rinsed several times with distilled water before it was placed in to 1% aqueous hydrochloric acid solution for half hour.0.2 M sodium bicarbonate (NaHCO3) solution was prepared in a separate beaker and after about half hour, the film, treated with 1% HCl solution was placed in sodium carbonate solution for 15 mins. That process was taken place inside the fume hood on a hot plate, with no heat or stirring involved. Part II Another PVOH (MW of 22,000) film was prepared in 5 ml deionized water solution. After PVOH was dissolved in water, 1 ml of glutaraldehyde was added to the resultant mixture and the entire mixture was then placed in to Teflon plate. The solution was finally allowed to dry inside the fume hood. Part I Calculating The Mass of Sodium Bicarbonate: (0.2 mol NaHCO3/L) * (1 L/1,000 ml) * (200 ml) * (84.007 g NaHCO3/1mol NaHCO3) = 3.36 g NaHCO3 (sodium bicarbonate). Part III The second glutaraldehyde film was prepared except relace 20% of PVOH with PDMS. (0.4 g PVOH, 6 ml of water and 0.1 g of PDMS, 1 ml of glutaraldehyde). Note PDMS was in the liquid form, so we have to incorporate its density to calculate the appropriate volume that we use. (0.1g/965000Kg/m^3)* (1Kg/1,000 g) * (100 cm/1m) ^3 = 0.106 mL of PDMS used which was equivalent to 106 microliters added. Part IV Prepare 1L of glutaraldehyde fixant solution. We also mixed 1L of water with 200 g of Na2SO4. After Na2SO4 was dissolved, we added 20 ml of concentrated H2SO4. Part V Prepare 500 ml of 20 ppm sulfate ions solution as CuSO4 and Na2SO4 We performed dilutions of each solution in order to determine the accurate concentrations. CuSO4 : (159.02g/mol) * (0.00002 mol/L) * (1L/1000 mL) * (500 mL) = 0.0016 CuSO4 in 500 mL Na2SO4: (142.04g/mol) * (0.00002mol/L) * (1L/1000 mL) * (500 mL) = 0.0016 g Na2SO4 in 500 mL For Dilution of CuSO4: M1 V1 = M2 V2 (0.002 M) (V1) = (0.00002M) * (500 mL) Note V1=5 ml of the solution in 495 ml of water. In order to obtain the mass of 0.0016 g of CuSO4 in 500 ml of water. For Dilution of Na2SO4: 5 ml of the solution is mixed with 495 ml of water. In order to obtain 0.0014 g of Na2SO4 in 500 mL of water. Note: Both solutions were placed into separate volumetric flasks to make certain that the appropriate caps were on. Part VI Clays were filtered from September 9th. Data Add data and results here... Notes It was noticed that the film with lower molecular mass i.e., 22,000 MW is slightly thinner than the film with higher molecular mass i.e., 100,000. Also, please note that when preparing 20 ppm of CuSO4 and Na2SO4 solutions, HPLC graded water was used.