Lesson organisation This demonstration can be used at secondary level as an introduction to some of the ideas about kinetics. A limitation in part A would have been that the stirring would have affected the time it took for the solution to turn blue. Eye protection Balance 1 or 2 d. In conclusion, from part A the order of reaction of the iodate was found to be 2. Solution B is made up as follows: In part B the activation energy was found to be
Iodine Clock Reaction Lab Answers. It also makes a useful starting-point for a student investigation. Please help us feed and educate children by uploading your old homework! Our new website is coming soon. If the demonstration is being done for entertainment, the imaginative teacher will be able to think up some suitable patter. Description A solution of hydrogen peroxide is mixed with one containing potassium iodide, starch and sodium thiosulfate.
A chemical stop-clock – iodine clock reaction Rates and rhubarb. This collection of over practical activities demonstrates a wide range of chemical concepts and processes. Scaling up the volumes of solution that are mixed may help in a large room. In this lab, double replacement reactions between compounds were done in order to determine the equation and description of a new substance Solution A Note 1: It only takes seconds!
A solution of hydrogen peroxide is mixed with one containing coursewor iodidestarch and sodium thiosulfate. Schoolworkhelper Editorial Team https: The effect of concentration and temperature on reaction rate. There is no warning of when the blue colour is about to appear.
It is assumed that the order of reaction with respect to the bisulfate is zero, thus n is zero. Instead of the iodate ion concentration being changed the concentration of the bisulfate could have been changed by making it the limiting reactant experimment the balanced equations. Both solutions are colourless although solution A will be slightly cloudy.
Iodine clock reaction- Learn Chemistry
In search of more solutions: As soon as the iodine is formed, it reacts with the thiosulfate to form tetrathionate ions and recycles the iodide ions by the fast reaction: Iodine Clock Reaction Lab Answers. Some of the tubes may have gotten more stirred than others and this would have caused an inaccuracy in the times that were collected. The demonstration f Measure cm 3 of solution A and cm 3 of solution B in separate cm expfriment measuring cylinders. Conclusions that can be drawn from the data is that when the concentration of the potassium iodate solution was increased the rate of reaction decreased.
Sodium thiosulfatewater, Na 2 S 2 O 3. Solids, liquids and gases.
The Iodine Clock Investigation
In conclusion, from part A the order of reaction of the iodate was found to be 2. Additional notes 1 Hydrogen peroxide is capable of oxidising thiosulfate ions to tetrathionate ions but the courseork is too slow to affect this demonstration.
The experiment should have been done both ways to have the most accurate results.
This is one of a number of reactions loosely called the iodine clock. This demonstration can be used at secondary level as an introduction to expriment of the ideas about kinetics.
See Technician notes about using dilute ethanoic acid as a less hazardous alternative.
As well another way that the procedure can be improved upon is to perform the lab like a titration lab using a burette, flask and the indicator. It also makes a useful starting-point for a student investigation. This assumption will be further evaluated in the evaluation of the weaknesses and limitations.
Iodine Clock Reaction Lab Answers
Expeiment until all the solids have dissolved and allow to cool to room temperature. All throughout the lab the assumption that is made throughout the lab is that the bisulfate ion has a reaction order of zero. Procedure Solution A is made up as follows: Another relationship that can be seen between the rate constant and the temperature is that as the temperature increased the rate constant increased as well. If the demonstration coursewrok being done for entertainment, the imaginative teacher will be able to think up some suitable patter.