6th Year: The Reox Titration between Iodine and Thiosulphate

This is the third of our four redox titrations.

The data sheet for the reaction is available in the box on the right in the 6th Year folder. It should be downloaded and studied before you attempt the titration.

There is a slight 'twist' to this titration in that we initially titrate the red/brown solution of iodine to a pale yellow with thiosulphate. A few drops of a fresh starch solution is then added which turns the solution blue/black. The titration is continued until there is a colour change from blue/black to colourless.

We cannot judge with our eyes when the pale yellow turns colourless so we use starch as an indicator.

Again you may begin this expt as soo as you enter the lab on Monday afternoon. All chemicals will be on the side bench.

6th Year Redox Titration: Manganate Vs Iron

This expt for 6th year students will take place on Tuesday afternoon. It is important that you download the theory sheet called "Oxidation Titration" shown on the right and study it before attempting the titration.

Please also revise how to do titration calculations. You would have covered this in 5th year.

When you enter class on Tuesday afternoon, please go about setting up immediately as I plan to do a worked example of a full calculation after the experiment before we finish the lesson.

You may run a simulation of the experiment by visiting the following link: Redox Titration

5th Year Chemistry - Electronic Structure of the Atom - Class Slides

I have decided this time to place the slides on electronic structure of the atom up on the site for you to download before we finish the chapter. This will make your continued study easier and will help you to prepare for the coming classes.

5th Year Chemistry - Atomic Theory 1 - Class Slides

The first set of slides for ATOMIC THEORY 1 are now available to download. They are in the box on the right of this screen. Please download them and read them from your computer. If you wish you may print them out and file them away for your later revision.

I have also uploaded a short movie showing the effect of a hand-held magnet on cathode rays. Do have a look at it.

If you have any difficulties running the movie or any of the different animations on the slides just let me know in class on Monday.

Mr. O'Neill