Reaction Order of the Oxidation of Iodide by Persulphate in Neutral Solution
UCD School of Chemical &
Bioprocess Engineering
CHEN20040
Chemical & Bioprocess Engineering Laboratory I
Experiment: 1
Title: Reaction order of the oxidation of iodide by persulphate in neutral solution Name:
Lab Partner:
Group:
Experiment Performed:
Report Due:
Report Submitted:
Table of Contents
Abstract
Page
3
Materials and Methods
4
Results and Discussion
5
Conclusion
10
Report Questions
11
Appendices
Appendix A. Experimental Data
12
Appendix B. Sample Calculations
13
Appendix C. Nomenclature
14
Appendix D. References
15
2
Abstract
The purpose of this experiment was to determine the reaction order of the oxidation of iodine with respect to persulphate (part 1) and iodine (part 2). For part 1 of the experiment, this was done by titrating a solution of 50 cm3 of diluted 0.0225M persulphate and 250 cm3 of 0.4M potassium iodine against a 50 cm3 solution of 0.01 M solidum thiosulphate, using 3 ml of 2% starch as an indicator. For part 2, a solution of 25cm3 of iodine and persulphate, and 25 cm3 of
0.04M potassium chloride was titrated against the same amount of thiosulphate. Using the titre values Tt (ml), time (s) and Tinf, graphs were plotted in order to obtain the rate constants k’, k’’ and hence ‘n’, the reaction order.
For part 1, a value of 0.96 was obtained for the slope of the graph, which is approximately equal to 1, indicating that this is a first order reaction. A value of 0.001 was then obtained for k’, the rate constant.
For part 2, the slope was found to be 0.91 which is again approximately equal to 1. A value of
0.0005 was obtained for k’’. The values of k’and k’’ were used to calculate the reaction order ‘n’, which was found to be 1, indicating a first order reaction.
3
Materials & Methods
The materials and methods were carried out as described in the CHEN20040: Chemical and
Bioprocess Engineering Laboratory 1 Manual (Kieran 2013, pages 1
Bioprocess Engineering
CHEN20040
Chemical & Bioprocess Engineering Laboratory I
Experiment: 1
Title: Reaction order of the oxidation of iodide by persulphate in neutral solution Name:
Lab Partner:
Group:
Experiment Performed:
Report Due:
Report Submitted:
Table of Contents
Abstract
Page
3
Materials and Methods
4
Results and Discussion
5
Conclusion
10
Report Questions
11
Appendices
Appendix A. Experimental Data
12
Appendix B. Sample Calculations
13
Appendix C. Nomenclature
14
Appendix D. References
15
2
Abstract
The purpose of this experiment was to determine the reaction order of the oxidation of iodine with respect to persulphate (part 1) and iodine (part 2). For part 1 of the experiment, this was done by titrating a solution of 50 cm3 of diluted 0.0225M persulphate and 250 cm3 of 0.4M potassium iodine against a 50 cm3 solution of 0.01 M solidum thiosulphate, using 3 ml of 2% starch as an indicator. For part 2, a solution of 25cm3 of iodine and persulphate, and 25 cm3 of
0.04M potassium chloride was titrated against the same amount of thiosulphate. Using the titre values Tt (ml), time (s) and Tinf, graphs were plotted in order to obtain the rate constants k’, k’’ and hence ‘n’, the reaction order.
For part 1, a value of 0.96 was obtained for the slope of the graph, which is approximately equal to 1, indicating that this is a first order reaction. A value of 0.001 was then obtained for k’, the rate constant.
For part 2, the slope was found to be 0.91 which is again approximately equal to 1. A value of
0.0005 was obtained for k’’. The values of k’and k’’ were used to calculate the reaction order ‘n’, which was found to be 1, indicating a first order reaction.
3
Materials & Methods
The materials and methods were carried out as described in the CHEN20040: Chemical and
Bioprocess Engineering Laboratory 1 Manual (Kieran 2013, pages 1
References: Mak, C.H. (2009) ‘Electrolyte Solutions’ [online]. Availble from: http://wwwscf.usc.edu/~chem430a/scans/08.pdf [Accessed 11/11/13] Brӧnsted, J.N. and Livingston, R. (1927) ‘The velocity of ionic reactions’ Journal of the American Chemical Society, 49 [online]. Available form: http://pubs.acs.org/doi/pdf/10.1021/ja01401a015 [Accessed 11/11/13] 19