Redox Titration Lab Report

Chemical Background

A redox reaction is a chemical reaction that only happens when oxidation and reduction process take place simultaneously. A redox reaction helps determine the concentration of a solution containing oxidizing or reducing agents. The concentration of potassium permanganate solution, KMnO4 was not given in the experiment that was carried out. By conducting a redox titration, the concentration of potassium permanganate solution, KMnO4 can be determined.

Discussion Before performing the titration, the burette was rinsed three times with distilled water and rinsed once with potassium permanganate solution. The volumetric pipette was also rinsed three times with distilled water and after that rinsed once with iron

There was an increase in temperature after the concentrated sulphuric acid was added into the volumetric flask containing the iron (II) solution, the outer glass of the volumetric flask was warm. The reason why concentrated sulphuric acid was added is so that the iron (II) solution is stabilized. This is because Iron (II) is vulnerable to be oxidized but the oxidation of iron (II), 〖Fe〗^(2+) to iron (III), 〖Fe〗^(3+) is unable to take place in the presence of an acid. Sulphuric acid which is a strong acid will react with potassium permanganate solution, which is an oxidizing agent, to produce high concentration of hydrogen ions in order to convert oxygen from the potassium permanganate solution into water molecules. Therefore, diluted sulphuric acid was added to the standard iron (II) solution before titration took place. The color of the iron (II) solution changes from pale yellow to pale pink when titration was taking place. The true value of the concentration of potassium permanganate solution is 0.0186 mol/L but the concentration obtained through titration was 0.0176 mol/L. This shows that the results found in the experiment is inaccurate. However, the precision of the results is high as the concordant values were obtained at the first 3 trials of the

The eye level may have not been perpendicular to the meniscus of the liquid when recording a measurement and this may have caused inconsistent readings when repeating the redox titration. Several steps can be taken to improve this error. A ruler should be used to align the eye level of the reader and the meniscus of the liquid. Due to the dark intensity of color of the permanganate solution, a paper should be placed on the outer glass of the burette by placing the tip of the paper at the meniscus when recording the initial value and final value of the permanganate solution. Another random error that occurred is the false detection of the end point when titrating the permanganate solution into the conical flask. The tap of the burette was not closed immediately as soon as the solution turned pale pink which caused the color intensity of the solution to be slightly lighter or darker. This would have provided inconsistent values when recording the final reading and initial reading of permanganate solution in the burette. To improve this error, the tap of the burette should be tightened to decrease the rate of droplets of permanganate solution dropping from the burette. This will make it easier for the student to completely stop the titration as soon as the end point of the solution is detected. Finally, not transferring the