Chem152_post lab 2 - Name and ID Number:Roberta JoEdwards...

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Name and ID Number:Roberta JoEdwards Section AG Lab Partner:Egnis Total Points = 60 pts (5 pts notebook, 55 pts template) Upon successful completion of the above information, its time to break out the software and graph it! This will be then using a spe DATA, GRAPHS AND CALCULATIONS 1 pt Creating the calibration curve: Ferroin: Concentration (M) Absorbance 1.25E-05 0.130 2.50E-05 0.280 2 pts 3.75E-05 0.510 5.00E-05 0.660 6.25E-05 0.730 Purpose and Method Clearly state the purpose of this part of the lab. Explain how this is accomplished in this experiment. What calculations do you need to perform? What measurements will be made? [Do not provide experimental details here]. How do you go from calculated/measured values to accomplishing stated purpose? ( 10 pts ) To put this is a simple way, the overall purpose of this lab is to prepare a series of standard solutions from one stock solution, and then use these standard solutions to plot a calibration curve. To do this, we must first obtain the stock solution of 6.25E-4 M of Ferroin solution. We then, using a volumetric flask, dilute the stock solution to the standard amount we desire (these amounts are found in pre-lab #2). The calculations for that are: XmL * 1L * Xmoles = moles of Ferroin 1000ML Moles of Ferroin * 1L * 1000mL = mL of stock solution moles Stock solution * 1L After that has been accomplished (and we should have 5 total standard solutions), we must then move on to preparing an iron sample to plot too. Remember, the iron tablet has been crushed into a powder! The overall goal in this part of the lab is to dilute the tablet, so that we might (after the lab is done) be able to calculate how much of the tablet was just Iron, and how much of it was the whole tablet. We do this by weighing out ~25mg of iron tablet powder. We then put it in a mix of 2mL of 0.1M Hcl, and heat it. Once that is completed, we will then transfer it (via syringe) to a volumetric flask. Make sure to get all the Iron tablet out! Add water to the mark on the flask, and stir well, U will then transfer 5mL to a new volumetric flask, where you will be adding to it hydroxylamine hydrochloride (which allows the Fe 2+ to react and become Fe3+), sodium acetate (which will neutralize any excess acid left over), and 1, 10-phenanthroline. Upon successful completion of the above information, its time to break out the software and graph it! This will be then using a spectrophotometer/computer station that is provided in the lab. Basically, you put the standard solutions (in order) into the said area, and the computer graphs it. You study it, and write down the information( later on, when your trying to find the concentration of the Ferroin complex, you can plot your data, and use Abs=slop * [Ferroin] + y-intercept to find the concentration). When all it said and
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This note was uploaded on 11/19/2009 for the course CHEM 152 taught by Professor Ashvinder during the Fall '09 term at Washington State University .

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Chem152_post lab 2 - Name and ID Number:Roberta JoEdwards...

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