IL·Experiment A: Redox Titration of(halicAcid ast is quite corrosive. Handle wit
ID: 550038 • Letter: I
Question
IL·Experiment A: Redox Titration of(halicAcid ast is quite corrosive. Handle with care, and immediately wash off, for at least 5 minutes, any that comes in contact with your skin. Salety Considerations: Wear your safety glasses Work in teams of two for this experiment, but you will work individually on the practical A. Diluting the KMn04 stock solution Step 1: A stock solution of concentrated KMnO, is available on the lab bench. Its approximate concentration is written on its label. From this stock solution, prepare 250 mL of approximate 0.020 M KMno, solution. Clearly show your calculations in the tep I Calculation area of the report sheet. (Because this solution concentration is approximate, you may use a graduated cylinder and beaker to prepare it.) Transfer the to your 500 mL plastic bottle and cap it. This diluted solution NOT the stock solution that you used to make it) should be standardized and used to titrate the unknown on the same day. If you need to use it the second day, you must run a known to check result, you must re-standardize. its concentration. If the result is appreciably different than the first day's Step 2: Rinse a clean buret with three 5 mL portions of your diluted KMnO, solution· (discard the rinses), then fill the buret with KMnO. Use proper technique in preparing the buret for titration (see "Introduction to Volumetric Analysis," in the Appendix).Explanation / Answer
molarity = moles of solute /litres of solution
solute is KMnO4 here,
Titration of KMnO4 against Oxalic acid is taking place
Preparation of standard solution of Oxalic acid [ m1v1 = m2v2 , using this volume of water required is 225 ml]
The molecular mass of crystalline oxalic acid is, H2C2O4.2H2O = 126
Weight of oxalic acid crystals required to prepare 1000 ml of 1 M solution = 126 g
for trial 1 ,
we have amount of solution is = 86.5 ml
final buret reading of kmno4 = 40 ml
moles of kmno4 = 0.02*40 = 0.8 moles
molarity of kmno4 = 0.8/.865 = 0.92