To determine the concentration of hydrogen peroxide
Extracts from this document...
Introduction
TO DETERMINE THE CONCENTRATION OF HYDROGEN PEROXYDE Aim: To determine the concentration and the volume strength of hydrogen peroxide in locally purchased solution using a redox titration. Introduction: Hydrogen Peroxide is a strong oxidizing agent, readily breaking down to form water and oxygen; and aqueous solution of hydrogen peroxide can be used for bleaching hair and used as an antiseptic for minor skin wounds. However, it is a highly efficient cellular poison. It is so devastating that we have an enzyme called "peroxidase" in our body that constantly removes any hydrogen peroxide that gets into our cells. In this experiment we will use a 20-volume hydrogen peroxide solution. It has to be diluted for the use. The solution will then be titrated against an acidified standard solution of potassium manganate(VII). The concentration of hydrogen peroxide in the titrated sample is then calculated, from which it is easy to calculate the concentration of the original sample. ...read more.
Middle
26.6 26.6 Readings used Volumetric Flask: 250ml + 0.15ml Volume of diluted H2O2 250ml+0.15ml Purity of potassium permanganate 99.0% Molarity of H2O2 ? Data Processing and Presentation: Correct answer given:- Molarity of H2O2- 6.54mol dm-3 Calculation From Titration: 5H2O2(aq) + 2MnO4-(aq) + 16 H+(aq) --> 10 H+(aq) + 5O2(g) + 5Mn2+(aq) + 20H2O(l) * Concentration of H2O2= no of moles/volume of H2O2 * Concentration of H2O2= No. of moles/10 ml * No. of moles= concentration x volume. However, we do not have the concentration of H2O2. * From the equation above we know that H2O2 and MnO4- are in the ratio 5:2. Therefore, form this ratio, if we can find the number of moles of MnO4- we can find the number of moles of H2O2. * Number of moles of MnO4- = concentration x volume = 0.01993(given) ...read more.
Conclusion
KMnO4- TOTAL ERROR PERCENTAGE= Systematic Errors: Even though my calculated value is within the random errors, some of the systematic errors which could have occurred are: * Judging the end point of the titration. * Diluting solutions while using some of the equipment * Overshot the mark in the volumetric flask. Conclusion: * From the titration results, the concentration of H2O2 is 6.63 mol/dm3 + 0.2 mol/dm3 * The expected value was 6.54mol/dm3 * The expected value was within the range of our calculated errors. 6.43mol/dm3 <--6.63 mol/dm3 -->6.83 mol/dm3 * Total error= [(6.63-6.54)/6.54] x 100 = 1.38% * Systematic errors are none or negligible as the calculated answer is within the limits of our calculated error. Evaluation: * The total error was less than the random errors. Our expected value was within the range of our random errors. Therefore, there were no systematic errors. Improvements: * Use better equipment- A grade glasswork. ...read more.
This student written piece of work is one of many that can be found in our International Baccalaureate Chemistry section.
Found what you're looking for?
- Start learning 29% faster today
- 150,000+ documents available
- Just £6.99 a month