Take a 05 g portion of your sample massed to the

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Take a 0.5 g portion of your sample (massed to the nearest mg by difference in your smallest beaker) and place it in a small beaker in the drying oven for roughly an hour at 115°C. (Note: your beaker need not be clean, but it must be dry prior to use.) Dry the sample to constant mass and determine the number of moles of water per mole of product molecule.
Expt. 2: Synthesis and Analysis of Potassium Tris(oxalato)ferrate(III) Trihydrate 2 – 6 Part C: Product Analysis – Oxalate in K 3 Fe(C 2 O 4 ) 3 ·3H 2 O The second analysis of your synthesized product is to determine the number of oxalate ions in the compound. Based on the compound’s formula, there should be 3 oxalate ions for every product molecule. The analysis will be done using the technique of titration. At the equivalence point, the number of moles of reactants are equal, according to the stoichiometry of the reaction. Here, potassium permanganate (KMnO 4 ) reacts with the oxalate ion (C 2 O 4 2 ) in the compound according to: 5 C 2 O 4 2– + 2 MnO 4 + 16 H + 10 CO 2 (g) + 2 Mn 2+ + 8 H 2 O (4) The first step in any titration is to standardize or determine the exact concentration of the titrant – in this case, KMnO 4 . To accomplish this, a pure sample of sodium oxalate, Na 2 C 2 O 4 , is precisely weighed out and titrated with the KMnO 4 solution. From the exact mass of the oxalic acid used and the stoichiometry of the reaction, the moles of KMnO 4 added can be calculated. Knowing the volume of KMnO 4 added during the titration, the exact concentration of the KMnO 4 solution can then be calculated. Since experiments can have errors associated with them, the entire lab will share their calculated concentration of KMnO 4 solution, and an average will be calculated. Use this average as the concentration of KMnO 4 solution in all subsequent calculations. Part C1: Standardization of a Permanganate Solution Thoroughly clean, rinse, and dry your 400 mL beaker and a 250 mL Erlenmeyer flask. You will use the Erlenmeyer flask for storage of your KMnO 4 solution. Obtain 100 mL of the approximately 0.014 M KMnO 4 solution. Weigh out a 0.12- to 0.15-g sample of oven-dried sodium oxalate (available on the TA bench) on a weighing dish using the analytical balance. Record the exact mass to as many decimal places as permitted by the balance. Transfer the weighed sodium oxalate to a clean, 250- mL Erlenmeyer flask (it need not be dry). Add 40 to 50 mL of distilled water to the flask containing the Na 2 C 2 O 4 . Add 10 mL of 3 M H 2 SO 4 to the sodium oxalate solution using your graduated cylinder (which gives an acidic solution for the titration). Obtain a buret from the buret rack and rinse it, first with distilled water and then with a 5 mL portion of the KMnO 4 solution. Be sure to rinse the tip, as well as the upper portion of the buret. Save this KMnO 4 rinse solution for later treatment and disposal. Using a clean, dry funnel, fill the buret to a level just above the zero mark with KMnO 4 solution and then remove the funnel. To fill the tip at the bottom of the buret open the stopcock by wrapping your left hand around the buret and grasping the stopcock between your left thumb and first two fingers and

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