The reacting mole ratio is 2: The graph below shows what happens to a reactant with a half—life of 5 minutes. Connect the graphs with the following: Orders of reaction can ONLY be determined by rate experiments From the point of view of coursework projects the detailed analysis described above is required, but quite often in examination questions a very limited amount of data is given and some clear logical thinking is required. Apparatus and Chemicals selection of syringes cm3 glass beakers white tile timer distilled water 1 mol dm?

A series of experiments will be carried out in which only the concentration of the iodide ions will be varied. Since the gradient rate changes with concentration, it cannot be a zero order reaction. In reality the results would be not this perfect and you would calculate k for each set of results and quote the average! We can now examine theoretically, the effect of changing individual concentrations on the rate of reaction of a more complicated rate expression of the form.. Some rate data for the inversion of sucrose is given below.

The Iodine Clock Investigation

Collecting a gaseous product in a gas syringe or inverted burette. A way to make the measurements more precise is to use the same error margins on all instruments thus allowing a constant error margin.

The initial rate is taken as the positive tangent – gradient for the curve at the point 0,0. CH 3 3 C—Cl concentration. Give a valid conclusion to this experiment with an explanation.

Examples of obtaining rate data. How About Make It Original? A graph is drawn of CH 3 3 CCl concentration versus time. oidine


iodine clock reaction coursework

Example of a rate expression. Have your say about doc b’s website. You can think the other way round i. The graph below shows what happens to a reactant with a half—life of 5 minutes. We will write a custom essay sample on. The idea is that somehow you test for the order with an appropriate linear courseworo Describe any sources of error in your experiment.

A single set of reaction rate data at a temperature of K. You just substitute the values into the full rate expression: Orders of reaction can only be obtained by direct experiment and their ‘complication’ are due to complications of the actual mechanism, which can be far from simple.

Iodine Clock Reaction: Concentration Effect Essay

The stirring motion was not kept constant and affects the rsaction it takes for the potassium iodide to react with sodium thiosulphate as the rate of reaction would increase when the swirling motion is quick. For more details see section 7. Therefore the reaction is 1st order overalland the rate expression is Connect the graphs with the following: I’ve made the resction quite simple to follow the logic of the argument.

The reacting mole ratio is 2: We’ll occasionally send you account related and promo emails. This frequently causes problems!

iodine clock reaction coursework

Then you would get two negative gradients one steeper than ocursework other for the greater concentration. Its not a bad idea to repeat the calculation with another set of data as a double check! Apparatus and Chemicals selection of syringes cm3 glass beakers white tile timer distilled water 1 mol dm? There is no possible way to change the speed of reaction as it is a human flaw, therefore using a more precise instrument will be more appropriate for the lab.


A plot of HI concentration versus time above was curved showing it could not be a zero order reaction with respect to the concentration of HI. A non-linear graph of concentration versus time would suggest first or second order kinetics.

As seen in the graph, the line of best fit does not successful go through the first point 5,0.

Chemistry Coursework – by Arya Arun [Infographic]

The 2nd order graph tends to ‘decay’ more steeply than 1st order BUT that proves nothing! Sorry, but copying text is forbidden on this website.

iodine clock reaction coursework

By clicking “SEND”, you agree to our terms of service and privacy policy. There is another graphical way of showing the order c,ock respect to a reactant is 1st orderbut it requires accurate data showing how the concentration or moles remaining of a reactant changes with time within a single experiment apart from repeats to confirm the pattern.

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