In this project, a coordination compound, [Co(II)EDTA]2− will be prepared and its magnetic moment will be determined by NMR spectroscopy. A full picture of the clock behaviour will be presented through the combination of measurements provided by NMR spectroscopy alongside those obtained using more orthodox techniques such as UV spectrometry and pH measurements.
The experiment in Dr. Evans paper will replicated using the same measurements and techniques. This project is to serve as a proof of principle, showing that literature value can be replicated using a weaker magnet. The pH experiment will be used to illustrate the kinetic of the clock reaction. The concentration of the reactants and the pH of reacting mixture will be varied to determine their effect on the induction period of the clock reaction. …show more content…
The Gantt chart will be updated as the project proceeds.
4. Methodology
4.1 Chemicals
Sodium hydroxide, hydrochloric acid solution (0.1N), Manganese sulphate, EDTA disodium salt, cobalt chloride, t-butyl alcohol and hydrogen peroxide (30% by volume) were acquired from Sigma-Aldrich. The [Co(II)EDTA]2− complex was prepared as specified in 4.1.1.
4.1.1 Preparation of Co(II)EDTA]2−
A 2M stock solution of [Co(II)EDTA]2- was prepared by dissolving equimolar quantities of CoCl2 and EDTA in deionised water. As EDTA is acidic, sodium hydroxide granules were added to bring the mixture to the required pH. Two times the molar amount of EDTA is added. Additional sodium hydroxide and hydrochloric acid were added accordingly to achieve a pH of 4. A resultant pink solution is formed.
4.2 Techniques
4.2.1 pH measurements
A Jenway 3510 pH meter was used to study the pH of the clock reaction. pH readings were given to 3 decimal places; temperature was also provided. The pH meter is calibrated using buffer solutions (pH 4, 7 and 10).
Figure 9: Jenway 3510 pH