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UA CHEM 152 - Kinetics Summary & Proposal 2

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Chemical Thinking Kinetics Proposal 2 | 1Kinetics Summary & Proposal 2Your name: Rachel Taylor Your email: [email protected] lab partner’s names:Salma Ali Your lab partner’s emails: [email protected] TA’s name: Your lab section:All work must be very neat and organized. If you need to organize your thoughts, please use a separate sheet of paper. Proposals are a groupeffort. Please submit the completed document as a PDF to the Kinetics Proposal 2 D2L DropBox before exiting the lab.In your own words, the goal for this Kinetics Project is… The goal for this Kinetics Project is to determine the reaction rate, which is the speed at which a chemical reactionproceeds, and the rate constant which is the proportionality constant in the equation that expresses therelationship between the rate of a chemical reaction and the concentrations of the reacting substances. We haveto identify those two for the degradation under fixed conditions. This reason to we are performing this producer isto recommend the best conditions to prolong the shelf life of each drug.In your own words, the goal for this week of the Kinetics Project is….First, we must carry out the proposed plan to determine n, Kobs and t90 for the room temperature NaOH-mediated degradation of Phenolax, where the condition [NaOH]>>[X] exists. Next, the goal for this week of theKinetics Project is to come up with a proposal to determine the rater order, which is n, kobs, and t90 which is theshelf-life. When need to determine those constants for NaOH mediated degradation of the Pyoctanin at roomtemperature.Using the numbered steps from your proposal submitted last week, report your findings and observations for eachprocedural step in the left column. In the right column, explain what these observations indicate.Observation Explanation or IndicationWhen we implemented our proposed separation strategy, we observed the following results:1) After making a solution of 3000:100(NaOh:Phenolax) I was able to make the tableTime Absorbance0 0.8652 0.83212 0.60523 0.425Based on these observations and results, we concluded1) Based on the table I got using thespectrophotometer plus having the Molarabsorptivity and wavelength. I was able to usthe beer’s law formula.2) Through analyzing [Phx] vs time graph I wasable to find the beginning concentration andChemical Thinking Kinetics Proposal 2 | 232 0.31843 0.22753 0.12683 0.073130 0.027199 0.0162) After using the beer’s law I was able to get a table of [phx] vs time023.13E-083.01E-0812 2.19E-0823 1.54E-0832 1.15E-0843 8.22E-0963 4.56E-0983 2.64E-09130 9.78E-10199 5.80E-103) I found that at 90% the concentration will be2.8196x10-8.Next I divided by my rate constantand got a time of 3.19 seconds4) After I completed the ln[Phx] and 1/[Phx]equations I got the following tables: Time ln[phx]2-17.31912-17.63723-17.98932-18.2843 -when it reaches 90% (t90) and the Rateconstant and k obs3) After I did ln[Phx] and 1/[Phx] to give me thevalues needed for my new tables.4) I was able to determine the rate order was 2Chemical Thinking Kinetics Proposal 2 | 318.61763-16.90383-19.752130-20.746199-21.268 Time 1/[Phx]233222591.31245662100.42364935064.93286956521.743121654501.63219298245.83378787878.130102249488199172413793Chemical Thinking Kinetics Proposal 2 | 4Based on your exploration, , propose a plan and justify each step to experimentally determine n, kobs and t90 at room temperature that can be applied to PYOCTANIN, where the condition [NaOH] >> [X] exists as described in theGuide. Please NUMBER your procedural steps. Please NUMBER your procedural steps. Procedural Step Justification based on data1) Place the three ratios of NaOH of Pyoctanin tothe spectrometer. (3mL:60uL, 3mL:65uL,3mL:70uL)2) Use the absorbance values from thespectrophotometer and molar absorptivity of8.65 x104cm-1 M-1 Beer’s law in order to findthe concentration.3) Place the concentration values found in theprevious step into an excel graph ofconcentration vs time4) Next graph of the concentration will be in [X]vs. t and 1/[X] vs.( Analyze R^2 of all graphs)5) Find 90% o the concentration and then on theconcentration vs T graph [X] find the time yourvalue is place at1) This will give you the absorbance at differenttime stamps which will allow you findconcentration.2) Will give you the values needed for aconcentration vs time plot3) The graph will allow you to find t90 n, andkobs4) Can reveal the rate order n of the reaction andpermit determination of the observed rateconstant, kobs5) This will be your t90 value.Chemical Thinking Kinetics Proposal 2 | 5Technical Skill EvaluationGraphical Determination of the Rate Order n and Observed Rate Constant, kobs (10 p). Using Excel prepare three plots ([Phx] vs. t, ln[Phx] vs. t, and 1/[Phx] vs. t) to enable determination of the order n (the rate order with respect to the molar concentration of Phenolax) and the observed rate constant, kobs, for the base-mediated Phenolax degradation. Carefully reproduce (draw) or paste-in the three graphs giving the linear equation with R2 value (from Excel). Clearly explain how you derived the values of n and kobs using the plots.After analyzing the graphs I was able to determine the rate order with respect to the molar concentration of phenolax is the second order. I came to this conclusion through my analyzation of the graphs R^2 values. The 1/ [phx] R^2 value was the closest value to one. This gave me the Rate law of k[Phx]^2. I then substituted in the slope given to me and got K and the concentration of Phx. This gave me the Rate constant of 8.83369502x10-9.Chemical Thinking Kinetics Proposal 2 | 6Shelf-life Calculation (6 p). Based on your experimentally determined order n (the rate order with respect to the molar concentration of Phenolax) and rate constant, kobs, (both from the previous page) derive an expression for t90 (shelf-life) and calculate the t90. Show all work in sucha way that it justifies the mathematical relationships you are using.The equation I derived was : ( (3.13292285x10^-8)x .90)/ 8.83369502x10-9 %90 of concentration / Rate constant (2.8196x10^-8)/


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