reaction proceeds. Thus at the beginning of the titration some time is required to decolourize the oxalic acid solution but the reaction becomes very rapid as more Mn2+ ion is produced. A second interference occurs if the hot oxalic acid is left open to the air so that it decomposes by production of peroxide and water ;

                         H2C2O4 + O2  =  H2O2 + 2CO2

                                2H2O2  = O2 + 2H2O

 PRE-LABORATORY PREPARATION
1.      Material Safety Data 

Using the computers in the reading room, 217 Steacie Building, consult the online MSDS databases found at: http://www.carleton.ca/chemistry/safety/resources.html
Write into your lab manual, the hazards (both health and usage) associated with the following chemicals:
Iron(II) sulphate, potassium permanganate, sodium oxalate, sulphuric acid      phosphoric acid and oxalic acid.
For help on using the MSDS database search pages, consult appendix A.

 2.       Calculate the approximate weight of KMnO4 required to make 500 mL of 0.02 M KMnO4. Make 500 mL using your Florence flask one week in advance of doing this experiment (see schedule of experiments). 

3.      Why do we weigh by difference? 

4.      What is a blank in this experiment? 

5.      Write the balanced half reaction equations and the resulting complete reactions for: 
(a) the standardization of KMnO4 with Na2C2O4.
(b) the titration of Fe2+ with KMnO4

6.      What is the change in Oxidation Number of manganese in the reaction of KMnO4 with Fe2+ in acidic solution?