im investigating kinetics of the reaction of potassium manganate(VII) and oxalate ions.?

Question

what method could i use to experiment the effect of varying the concentrations of oxalic acid and to find the rate equation of the reaction?? plz help

Answer 1

First, you need some way to measure the rate of the reaction. Since KMnO4 is purple colored, that purple color will disappear as the reaction with oxalate takes place, so perhaps using a spectrophotometer to measure the disappearance of the purple color would be the easiest way to measure the rate of this reactions.

Next, you need to do a series of experiments in which you keep the concentration of one of the reactants constant and then systematically vary the concentration of the other. For each reaction, you'll measure the rate of the disappearance of the purple color. You can express the rate as change in absorbance/minute or something like that.

Then, you'll keep the concentration of the second reactant constant and vary the other one.

By comparing the concentrations and the rates of the reactions, you'lll be able to determine the rate equation.

Any general chemistry textbook will give you the details for arriving at the rate equation for data like this.

Answer 2

A method that you can use is by TITRATION. Acid-base titration=use the oxalic acid as the titrant (in the burette) and put the KMno4 in the volumetric flask. Use a methyl orange indicator (or any acid-base indicator). Add the indicator to the KMno4 and then titrate, shake the flask meanwhile the acid is pouring down. When the methyl orange and KMno4 shows a color change in the flask, it means that it has reached the equivalence point.
Do three trials. Take the time until the mixture in the flask changes color.

Use your result to calculate the rate equation.
Use this website to help you work out the rate equation:
http://www.chm.davidson.edu/ChemistryApplets/kinetics/MethodOfInitialRates.html