SIMULATIONCHEM 143: OXIDATION – REDUCTION TITRATION, LAB SIMULATIONThis week in lab you will not need to a2end the usual lab mee4ng 4mes. Instead you will bedirected to a computer simula4on of a redox 4tra4on. Some4me during the week you need tolog into this web site and perform the three different 4tra4ons. I highly encourage you to go toyour regular lab 4me and work on this lab there as your TA will be there for assistance ifneeded.h2p://group.chem.iastate.edu/Greenbowe/sec4ons/projecDolder/flashfiles/redoxNew/redox.htmlThe small tab on the leH of that page that reads “1. Select the Reac4on” allows you toselect the 4tra4on system to study. You will be assigned random concentra4ons of theoxidizing and reducing agent solu4ons (one in the bure2e and one in the receiving flask).AHer those values appear, you may use your cursor to slide the volume bar to add 4trantin large volumes. As you get close to the equivalence point (as will be noted in thechanging colors in the receiving flask) you should switch to the bu2on to add volume in0.020 mL increments un4l the color in the flask just barely remains. A good plan is toperform a “scout” 4tra4on where you quickly add 4trant with no inten4on of hiWng theexact equivalence point, but just get close so you will know the volume where you mustgo very slow (use the bu2on instead of the slider) when you use the “Repeat” bu2on todo another trial with the same concentra4ons. If you hit the “Reset” bu2on yourconcentra4ons will change and you will need to do another “scout” 4tra4on.Use the data tables provided to record all per4nent data for each of the three 4tra4onsimula4ons.Show the calcula4ons, and answers, that provide the correct molari4es of each of thesolu4ons in the flasks.Answer the discussion ques4ons that follow the data table and calcula4ons. Review thechapter on electrochemistry in your textbook if you are struggling with the content inthe discussion ques4ons.If you encounter technical difficul4es try using the Help Center computers. Contact yourTA about any chemical or lab write up clarifica4ons.KMnO4 + Fe2+* show your calcula4ons — use the stoichiometry from the balanced equa4on and the general4tra4on equa4on:K2Cr2O7 + Sn2+* show your calcula4ons — use the stoichiometry from the balanced equa4on and the general4tra4on equa4on:DATA TABLE:M KMnO4 Vol KMnO4needed Vol Fe2+ sample * M Fe2+M K2Cr2O7 Vol K2Cr2O7needed Vol Sn2+ sample * M Sn2+I2 + S2O32-* show the calcula4ons — use the stoichiometry from the balanced equa4on and the general4tra4on equa4on:DISCUSSION:1. Calculate the oxida4on number for one atom of Mn in the KMnO4 of the firstreac4on: _____2. Considering the change in oxida4on number of Mn in the product, how manyelectrons are gained or lost by Mn in KMnO4 when the reac4on is balanced?3. Briefly discuss a real world applica4on where redox 4tra4ons are used.M I2 Vol I2sample Vol S2O32- needed * M S2O32-
SIMULATION
07
Aug