The Iodide-Persulphate Reaction: the Effect of Concentration on Reaction Rate

3. Explain what caused the change in plasma ketone concentration over the course of the experiment.

3. Explain what caused the change in plasma ketone concentration over the course of the experiment.

There might have been more KOH solution added to the flask resulting in the observations to be wrong.

. The second term in first equations ([Ch2E-15]) and ([Ch2E-16]) becomes much smaller than the first term, because the detuning \Delta=\omega-\omega_{\textrm{A}}\ll\omega_{\textrm{A}}

The below figure indicates the 5 values I’ve chosen for K between 0.5 and 1 and shows how smooth the transition is from the original value to 1.

Consequently the iodine will react with the starch to create the coloured solution; this will only occur once the bisulphite is fully consumed (Unomaha, 2016). Throughout the course of these chemical reactions, the rate at which the reaction occurs takes place

The triiodide ions created in equation (1) are reduced back into iodide ions by the sodium thiosulphate ions in the solution. This phase of the clock reaction is shown in equation (2)

4) Try and propose a mechanism for the reaction using the orders of reaction taking into account the iodine, propanone and sulphuric acid.

This equation resulted in being left with a negative final percentage error. Which was easy to fix, as it just had to be turned into a positive for the final answer. It is evident to see how the theoretical results increase each time approximately -620 KJ/mol. This is as each carbon chain increases so does the amount of bonds associated with it.

The time step 0.005fs gives a mean energy error (standard deviation) of around 0.01% of the mean value. This is an acceptable level of accuracy. The hottest system has been chosen for this test because it will have the most kinetic energy and atoms will move the most. Therefore the system will be the most volatile and have the biggest uctuations from the mean energy value. Thus a time step at this high temperature will be as accurate or more at any lower temperature.

However, looking back at the analysis section, the relative atomic mass values I found were not exactly 6.9 as presented in the periodic timetable. Method (1) gave me 8.28; a difference of 1.38 and method (2) gave me 7.37, a difference of 0.43 to the real/reference value. Therefore

It was the triiodide ion that is mostly responsible for the orange-red-brown color since iodide was colourless and since iodine is not very soluble in water. As the reaction was progressing, the coloured solution began to fade to orange, yellow and finally became colourless.  As these colour changes occur, the temperature of the solution was decreasing gradually until it has finally reached room temperature.  This change in colour was due to two factors.  First, all of the solid and dissolved iodine had reacted with the zinc to produce iodide and zinc ions, both of which are colourless substances.  Secondly, the red-brown solution of triiodide ions also reacted with zinc metal to produce the colourless iodide ions.

The ratio between the gradients for run 1 and run 2 is 1:2 as 0.4/0.263 is approximately half, whereas the gradient for runs 2 and 3 is 3:2 as 0.563/0.4 is approximately 1.5.

Step 10: i = 0 to 30 do: K  0.3  i / 100

Qt = amount of drug dissolved in time t, Qo=initial amount of drug, k=zero order kinetics constant