To determine the effect of the nature of reactants on the average rate of a reaction.
You will need the following items for this experiment:
Oxalic acid ((COOH)2), iron(II) sulfate (FeSO4), potassium permanganate (KMnO4) and concentrated sulfuric acid (H2SO4)
a spatula, two test tubes, a medicine dropper, a glass beaker and a glass rod.
Concentrated H2SO4 can cause serious burns. We suggest using gloves and safety glasses whenever you work with an acid. Remember to add the acid to the water and to avoid sniffing the acid. Handle all chemicals with care.
Label one test tube 1. Prepare an iron(II) sulfate solution in test tube 1 by dissolving two spatula tips of iron(II) sulfate in 10 cm3 of water.
Label the other test tube 2. Prepare a solution of oxalic acid in test tube 2 in the same way.
Prepare a separate solution of sulfuric acid by adding 2 cm3 of the concentrated acid to 10 cm3 of water. Remember always to add the acid to the water, and never the other way around.
Add 2 cm3 of the sulfuric acid solution to the iron(II) sulfate and oxalic acid solutions respectively.
Using the medicine dropper, add a few drops of potassium permanganate to the two test tubes. Observe how quickly the potassium permanganate solution discolours in each solution.
You should have seen that the the potassium permanganate discolours in the oxalic acid solution much more slowly than in the iron(II) sulfate solution.