Shanxian Chemical
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Determination of Hydrogen Peroxide by Titration
Determination of Hydrogen Peroxide by Peroxide Titration
I. INTRODUCTION
As an important chemical substance, hydrogen peroxide is widely used in many fields. Accurate determination of its content is of key significance for industrial production and scientific research. Peroxide titration is a commonly used and effective method for determining hydrogen peroxide content. The purpose of this paper is to elaborate the principle, operation process and result analysis of this method.
2. Experimental principle
Hydrogen peroxide can be quantitatively oxidized by potassium permanganate in acidic medium. The reaction equation is as follows:
\ (2KMnO_ {4} + 5H_ {2} O_ {2} + 3H_ {2} SO_ {4} = K_ {2} SO_ {4} + 2MnSO_ {4} + 8H_ {2} O + 5O_ {2}\ uparrow\)
Using this reaction, the hydrogen peroxide solution can be titrated with potassium permanganate standard solution. According to the consumption of potassium permanganate solution, the content of hydrogen peroxide can be calculated according to the stoichiometric relationship.
III. Experimental instruments and reagents
1. ** Instrument **: acid burette, conical flask, pipette, volumetric flask, analytical balance.
2. ** Reagents **:
-\ (KMnO_ {4}\) solid (analytically pure) for the preparation of potassium permanganate standard solution.
-\ (H_ {2} SO_ {4}\) solution (\ (3mol/L\)) to provide an acidic reaction medium.
- hydrogen peroxide sample solution.
- sodium oxalate solid (reference substance) for the calibration of potassium permanganate solution.
IV. EXPERIMENTAL STEP
1. **\ (KMnO_ {4}\) Standard Solution Preparation and Calibration **
- ** Preparation **: Weigh about\ (1.6 g KMnO_ {4}\) solid, place in\ (500mL\) beaker, add an appropriate amount of water to dissolve, transfer to a brown reagent bottle, dilute to about\ (1000mL\), shake well, leave\ (7 - 10\) days in the dark, then filter with a glass sand core funnel to remove\ (MnO_ {2}\) and other impurities.
- ** Calibration **: accurately weigh\ (0.15 - 0.20g\) reference sodium oxalate in\ (250mL\) conical flask, add\ (50mL\) water and\ (15mL 3mol/L H_ {2} SO_ {4}\) solution, heat to\ (75 - 85 ^ {\ circ} C\), while hot with the\ (KMnO_ {4}\) solution to be calibrated, the titration speed should be slow at the beginning, to be produced in the solution\ (Mn ^ {2 + }\) , the titration speed can be appropriately accelerated, but still need to be added dropwise until the solution is reddish and\ (30s\ ) does not fade, is the end point. Parallel calibration\ (3\) times, calculate the exact concentration of\ (KMnO_ {4}\) standard solution.
2. ** Determination of hydrogen peroxide content **
- Pipette accurately\ (10.00mL\) hydrogen peroxide sample solution to\ (250mL\) conical flask, add\ (15mL 3mol/L H_ {2} SO_ {4}\) solution.
- Titration with calibrated\ (KMnO_ {4}\) standard solution until the solution is reddish and does not fade within\ (30s\), which is the endpoint. Record the volume of consumed\ (KMnO_ {4}\) standard solution. Parallel determination\ (3\) times.
V. Data recording and processing
1. **\ (KMnO_ {4}\) calibration of standard solution **
| number of calibrations |\ (m (Na_ {2} C_ {2} O_ {4})/g \) | \( V (KMnO_ {4})/m L \) | \( c (KMnO_ {4})/(mol/L )\) | \( c (KMnO_ {4}) \) mean\ ((mol/L) \) | relative deviation \((\%)\) |
|---|---|---|---|---|---|
| 1 | | | | | |
| 2 | | | | | |
| 3 | | | | | |
According to the reaction equation:\ (2KMnO_ {4} + 5Na_ {2} C_ {2} O_ {4} + 8H_ {2} SO_ {4} = K_ {2} SO_ {4} + 2MnSO_ {4} + 5Na_ {2} SO_ {4} + 10CO_ {2}\ uparrow + 8H_ {2} O\), we get\ (n (KMnO_ {4}) =\ frac {2} {5} n (Na_ {2} C_ {2} O_ {4 }) \), and then calculate the concentration of\ (KMnO_ {4}\) standard solution\ (c (KMnO_ {4}) =\ frac {2m (Na_ {2} C_ {2} O_ {4}) } {5M (Na_ {2} C_ {2} O_ {4}) V (KMnO_ {4}) }\), where\ (M (Na_ {2} C_ {2} O_ {4}) \) is the molar mass of sodium oxalate.
2. ** Determination of hydrogen peroxide content **
| Number of measurements |\ (V (H_ {2} O_ {2})/m L \) | \( V (KMnO_ {4})/m L \) | \( c (H_ {2} O_ {2})/(mol/L )\) | \( c (H_ {2} O_ {2}) \) Mean\ ((mol/L) \) | Relative deviation \((\%)\) |
|---|---|---|---|---|---|
| 1 | 10.00 | | | | |
| 2 | 10.00 | | | | |
| 3 | 10.00 | | | | |
According to the reaction equation:\ (2KMnO_ {4} + 5H_ {2} O_ {2} + 3H_ {2} SO_ {4} = K_ {2} SO_ {4} + 2MnSO_ {4} + 8H_ {2} O + 5O_ {2}\ uparrow\), we can get\ (n (H_ {2} O_ {2}) =\ frac {5} {2} n (KMnO_ {4}) \), then the concentration of hydrogen peroxide solution\ (c (H_ {2} O_ {2}) =\ frac {5c (KMnO_ {4}) V (KMnO_ {4}) } {2V (H_ {2} O_ {2 })}\)。
6. Precautions
1.\ (KMnO_ {4}\) The solution is easy to decompose in light and should be stored in a brown bottle, and its concentration needs to be re-calibrated after a period of time.
2. When calibrating the\ (KMnO_ {4}\) solution, the temperature of the sodium oxalate solution should not be too high, otherwise\ (H_ {2} C_ {2} O_ {4}\) will partially decompose.
3. In the titration process, at the beginning of the\ (KMnO_ {4}\) solution is dropped slowly. After the\ (Mn ^ {2 + }\) , due to the catalytic action of\ (Mn ^ {2 + }\) , the reaction speed is accelerated. At this time, the titration speed can be appropriately accelerated, but it still needs to be added dropwise to avoid too violent reaction.
Through the above experimental steps and data processing, the content of hydrogen peroxide can be accurately determined, providing reliable data support for applications in related fields.
I. INTRODUCTION
As an important chemical substance, hydrogen peroxide is widely used in many fields. Accurate determination of its content is of key significance for industrial production and scientific research. Peroxide titration is a commonly used and effective method for determining hydrogen peroxide content. The purpose of this paper is to elaborate the principle, operation process and result analysis of this method.
2. Experimental principle
Hydrogen peroxide can be quantitatively oxidized by potassium permanganate in acidic medium. The reaction equation is as follows:
\ (2KMnO_ {4} + 5H_ {2} O_ {2} + 3H_ {2} SO_ {4} = K_ {2} SO_ {4} + 2MnSO_ {4} + 8H_ {2} O + 5O_ {2}\ uparrow\)
Using this reaction, the hydrogen peroxide solution can be titrated with potassium permanganate standard solution. According to the consumption of potassium permanganate solution, the content of hydrogen peroxide can be calculated according to the stoichiometric relationship.
III. Experimental instruments and reagents
1. ** Instrument **: acid burette, conical flask, pipette, volumetric flask, analytical balance.
2. ** Reagents **:
-\ (KMnO_ {4}\) solid (analytically pure) for the preparation of potassium permanganate standard solution.
-\ (H_ {2} SO_ {4}\) solution (\ (3mol/L\)) to provide an acidic reaction medium.
- hydrogen peroxide sample solution.
- sodium oxalate solid (reference substance) for the calibration of potassium permanganate solution.
IV. EXPERIMENTAL STEP
1. **\ (KMnO_ {4}\) Standard Solution Preparation and Calibration **
- ** Preparation **: Weigh about\ (1.6 g KMnO_ {4}\) solid, place in\ (500mL\) beaker, add an appropriate amount of water to dissolve, transfer to a brown reagent bottle, dilute to about\ (1000mL\), shake well, leave\ (7 - 10\) days in the dark, then filter with a glass sand core funnel to remove\ (MnO_ {2}\) and other impurities.
- ** Calibration **: accurately weigh\ (0.15 - 0.20g\) reference sodium oxalate in\ (250mL\) conical flask, add\ (50mL\) water and\ (15mL 3mol/L H_ {2} SO_ {4}\) solution, heat to\ (75 - 85 ^ {\ circ} C\), while hot with the\ (KMnO_ {4}\) solution to be calibrated, the titration speed should be slow at the beginning, to be produced in the solution\ (Mn ^ {2 + }\) , the titration speed can be appropriately accelerated, but still need to be added dropwise until the solution is reddish and\ (30s\ ) does not fade, is the end point. Parallel calibration\ (3\) times, calculate the exact concentration of\ (KMnO_ {4}\) standard solution.
2. ** Determination of hydrogen peroxide content **
- Pipette accurately\ (10.00mL\) hydrogen peroxide sample solution to\ (250mL\) conical flask, add\ (15mL 3mol/L H_ {2} SO_ {4}\) solution.
- Titration with calibrated\ (KMnO_ {4}\) standard solution until the solution is reddish and does not fade within\ (30s\), which is the endpoint. Record the volume of consumed\ (KMnO_ {4}\) standard solution. Parallel determination\ (3\) times.
V. Data recording and processing
1. **\ (KMnO_ {4}\) calibration of standard solution **
| number of calibrations |\ (m (Na_ {2} C_ {2} O_ {4})/g \) | \( V (KMnO_ {4})/m L \) | \( c (KMnO_ {4})/(mol/L )\) | \( c (KMnO_ {4}) \) mean\ ((mol/L) \) | relative deviation \((\%)\) |
|---|---|---|---|---|---|
| 1 | | | | | |
| 2 | | | | | |
| 3 | | | | | |
According to the reaction equation:\ (2KMnO_ {4} + 5Na_ {2} C_ {2} O_ {4} + 8H_ {2} SO_ {4} = K_ {2} SO_ {4} + 2MnSO_ {4} + 5Na_ {2} SO_ {4} + 10CO_ {2}\ uparrow + 8H_ {2} O\), we get\ (n (KMnO_ {4}) =\ frac {2} {5} n (Na_ {2} C_ {2} O_ {4 }) \), and then calculate the concentration of\ (KMnO_ {4}\) standard solution\ (c (KMnO_ {4}) =\ frac {2m (Na_ {2} C_ {2} O_ {4}) } {5M (Na_ {2} C_ {2} O_ {4}) V (KMnO_ {4}) }\), where\ (M (Na_ {2} C_ {2} O_ {4}) \) is the molar mass of sodium oxalate.
2. ** Determination of hydrogen peroxide content **
| Number of measurements |\ (V (H_ {2} O_ {2})/m L \) | \( V (KMnO_ {4})/m L \) | \( c (H_ {2} O_ {2})/(mol/L )\) | \( c (H_ {2} O_ {2}) \) Mean\ ((mol/L) \) | Relative deviation \((\%)\) |
|---|---|---|---|---|---|
| 1 | 10.00 | | | | |
| 2 | 10.00 | | | | |
| 3 | 10.00 | | | | |
According to the reaction equation:\ (2KMnO_ {4} + 5H_ {2} O_ {2} + 3H_ {2} SO_ {4} = K_ {2} SO_ {4} + 2MnSO_ {4} + 8H_ {2} O + 5O_ {2}\ uparrow\), we can get\ (n (H_ {2} O_ {2}) =\ frac {5} {2} n (KMnO_ {4}) \), then the concentration of hydrogen peroxide solution\ (c (H_ {2} O_ {2}) =\ frac {5c (KMnO_ {4}) V (KMnO_ {4}) } {2V (H_ {2} O_ {2 })}\)。
6. Precautions
1.\ (KMnO_ {4}\) The solution is easy to decompose in light and should be stored in a brown bottle, and its concentration needs to be re-calibrated after a period of time.
2. When calibrating the\ (KMnO_ {4}\) solution, the temperature of the sodium oxalate solution should not be too high, otherwise\ (H_ {2} C_ {2} O_ {4}\) will partially decompose.
3. In the titration process, at the beginning of the\ (KMnO_ {4}\) solution is dropped slowly. After the\ (Mn ^ {2 + }\) , due to the catalytic action of\ (Mn ^ {2 + }\) , the reaction speed is accelerated. At this time, the titration speed can be appropriately accelerated, but it still needs to be added dropwise to avoid too violent reaction.
Through the above experimental steps and data processing, the content of hydrogen peroxide can be accurately determined, providing reliable data support for applications in related fields.
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