CHEMISTRY 1211 L-ANALYSIS OF COBALT OXALATE- determination of oxalate content.

background  on titration cobalt oxalate hydrate    





The number of moles of oxalate ion in a sample may be determined by titrating a solution of the sample with a solution containing a known number of permanganate ions. This reaction is:

5C2O42- (aq) + 2MnO4 -(aq)

--->

 10CO2(g) + 2Mn2+(aq)+  +8H2O(ℓ)
     

 

    

Note that this is not a one to one molar ratio and therefore M1V2=M2V2 CAN NOT BE USED.

The molar ratio of oxalate to permanganate is 5 moles C2O42- to 2 moles MnO4 - .

  1. To find the moles of oxalate, set up the ratio as follows:
5 moles C2O42-  x A moles   MnO4 -

x 1  liter MnO4 -

 x B mL MnO4 -
2 moles MnO4 - liter MnO4 -

1000mL MnO4 -

  

Where

A= the concentration of your KMnO4 solution determined by standardization with 0.100M Na2C2O4

B = the mL of MnO4 - solution used to titrate the oxalate to the endpoint.

  1. Convert moles C2O42- to grams of C2O42- .
  2. Divide the grams of C2O42- by the mass of the sample and multiply by 100, to find the percent mass of   C2O42-in Coa(C2O4)b• cH20

 

 

 

references

Cobalt(II)_chloride

Oxalic acid

Oxalates

titration images  

video1 of cobalt oxalate titration

video2 of cobalt oxalate titration

determination of cobalt content