SQA
HIGHER
CHEMISTRY


The Effect of Temperature Change on Reaction Rate

UNIT 1
PPA2

The aim of this experiment is to find the effect of varying temperature on the rate of reaction between oxalic acid and an acidified solution of potassium permanganate:

Initially the reaction mixture is purple in colour due to the presence of the permanganate ions but it will turn colourless as soon as they are used up. This colour change allows us to follow the course of the reaction.

A series of experiments will be carried out in which only the temperature of the reaction mixtures will be varied. The concentrations and volumes of the reactants will be kept constant.

Since the amount of permanganate ions initially present will be the same in each experiment, the point at which the purple colour disappears will always represent the same extent of reaction. So if t is the time it takes for the colour change to occur then we can take 1/t as a measure of the reaction rate.

This simulated practical is not like a normal simulation, where you press the button and the work is done for you, in this simulation you must take the readings and decide how to plot the graphs.

Two versions of the practical have been produced, click on the option that best suits your needs:

  1. A partially completed experiment In this experiment the solutions have been made up for you, all you have to do is run the experiment and plot the results
  2. Full experiment In this experiment you can choose the volumes of chemicals to used for each run.

NOTE: To progress through the experiment, click on the "tabs" at the top of the program to change to different screens

Complete the tasks on each screen and then move on to the next tab to the right.

You can browse the different screens if you want at any time, in fact it's probably a good idea to have a look at them all before you start. As you might expect, some things later in the experiment won't work unless you've actually run the experiment.

If you get stuck, use the button at the top right of each screen.