Question

Answer these 3 parts of post-lab “ Redox Titrimetric Analysis of K3Fe(C2O4)3•3H2O” and put the answers in your conclusion and discussion.

1. a. In part 2 you determined the concentration of your KMnO₄ by titrating a solution of sodium oxalate. How would your concentration of KMnO₄ change if you had overshot the endpoint of your titration (added too much KMnO₄)?

b. If your calculation of the concentration of KMnO₄ from part 2 is incorrectly low, how will this affect your determination of concentration of K₃Fe(C₂O₄)₃ in part 3. Do not answer “it will off or wrong”, be specific if it will be higher or lower.

c. List three different potential sources of error (be specific) for this lab and indicate how they affected your results. For each state if the concentration of K₃Fe(C₂O₄)₃•3H₂O would be lower or higher.

(Please type the answers, don't write them on a paper)

Answer 1

a) The determined KMnO₄ solution concentration will be lower than the actual concentration. This is because, in order to determine the concentration of the KMnO₄ solution we have taken a specifically known concentration of sodium oxalate solution. However, we had erroneously added an excess of KMnO₄ solution. So, in our calculations we would use this higher value than the actual value that should have been recorded. Therefore, now for the same amount of sodium oxalate we have added a higher amount of KMnO₄ which would simply mean that our KMnO^{​​​​​​}₄ solution is of a lower concentration. Therefore, a lower concentration would be determined.

b) The calculated concentration of the complex would be lower than it's actual concentration. This is because our KMnO₄ solution is more concentrated than our calculated value. Therefore, less amount of KMnO₄ would be required. But, we are calculating using a lower value of KMnO₄ solution concentration. Therefore, the concentration of our complex will come out to be lower.

C) 1st error is over addition of The KMnO₄ solution from the burette during the standardisation process. This would lead to lower concentration value of the complex.

2nd error is higher addition of KMnO₄ solution from the burette during the estimation of the complex concentration. This would lead to a higher calculated concentration of the complex.

3rd error is the lower addition of KMnO₄ solution during the estimation of the complex concentration . This will lead to a lower calculated concentration of the complex.

Hope that helps! Thank You!