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Potassium permanganate can be obtained in a state of very high purity and is considered a primary standard.
Potassium permanganate can be obtained in a state of very high purity and is considered a primary standard.
False
The reaction of potassium permanganate with Fe^2+ ions produces Fe^3+ ions and requires eight hydrogen ions.
The reaction of potassium permanganate with Fe^2+ ions produces Fe^3+ ions and requires eight hydrogen ions.
True
One mole of MnO4^- requires five moles of Fe^2+ ions to undergo the oxidation-reduction reaction.
One mole of MnO4^- requires five moles of Fe^2+ ions to undergo the oxidation-reduction reaction.
True
Ammonium iron (II) sulfate can be used as a primary standard because it is sensitive to air.
Ammonium iron (II) sulfate can be used as a primary standard because it is sensitive to air.
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During the titration, the readings for potassium permanganate solution are taken from the bottom of the meniscus.
During the titration, the readings for potassium permanganate solution are taken from the bottom of the meniscus.
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Dilute sulfuric acid is added to the conical flask to provide hydroxide ions for the reaction.
Dilute sulfuric acid is added to the conical flask to provide hydroxide ions for the reaction.
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The manganese ion produced in the reaction with potassium permanganate is colorless.
The manganese ion produced in the reaction with potassium permanganate is colorless.
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The standardization of potassium permanganate solution can be performed using any reducing agent.
The standardization of potassium permanganate solution can be performed using any reducing agent.
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The end-point of the titration is indicated by a bright red color.
The end-point of the titration is indicated by a bright red color.
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One mole of MnO4^- reacts with 5 moles of Fe2+ in the reaction described.
One mole of MnO4^- reacts with 5 moles of Fe2+ in the reaction described.
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To calculate the concentration of the potassium permanganate solution, the average titration volume was used as 25 cm^3.
To calculate the concentration of the potassium permanganate solution, the average titration volume was used as 25 cm^3.
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The molarity of the ammonium iron(II) sulfate solution used was 0.12 M.
The molarity of the ammonium iron(II) sulfate solution used was 0.12 M.
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The total volume of sulfuric acid used to dissolve the five iron tablets was 250 cm^3.
The total volume of sulfuric acid used to dissolve the five iron tablets was 250 cm^3.
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The calculation for molarity of the potassium permanganate solution resulted in 0.0253 moles per litre.
The calculation for molarity of the potassium permanganate solution resulted in 0.0253 moles per litre.
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The mass of potassium permanganate in grams per litre was found to be 3.997 g/L.
The mass of potassium permanganate in grams per litre was found to be 3.997 g/L.
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All of the ground iron tablet material must be transferred to a 100 cm^3 volumetric flask for dilution.
All of the ground iron tablet material must be transferred to a 100 cm^3 volumetric flask for dilution.
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One mole of MnO4^- reacts with 5 moles of Fe2+ ions.
One mole of MnO4^- reacts with 5 moles of Fe2+ ions.
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The endpoint of the titration is indicated by a bluish color.
The endpoint of the titration is indicated by a bluish color.
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The concentration of potassium permanganate used in the titration is 0.015 M.
The concentration of potassium permanganate used in the titration is 0.015 M.
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Before using the burette, it is necessary to wash it with iron(II) solution.
Before using the burette, it is necessary to wash it with iron(II) solution.
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Five iron tablets with a total mass of 1.2 grams were used in the titration.
Five iron tablets with a total mass of 1.2 grams were used in the titration.
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To detect the end-point, the burette readings are taken from the bottom of the meniscus.
To detect the end-point, the burette readings are taken from the bottom of the meniscus.
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The reaction requires 8 moles of sulfuric acid for every mole of potassium permanganate.
The reaction requires 8 moles of sulfuric acid for every mole of potassium permanganate.
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The calculation of the concentration of the iron(II) solution is based on the average titration figure of 5.75 cm^3.
The calculation of the concentration of the iron(II) solution is based on the average titration figure of 5.75 cm^3.
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The molecular mass of FeSO4 is 154.
The molecular mass of FeSO4 is 154.
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Each tablet contains approximately 0.132 grams of FeSO4.
Each tablet contains approximately 0.132 grams of FeSO4.
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The percentage of iron in FeSO4 is 50%.
The percentage of iron in FeSO4 is 50%.
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A blue-black color appears when starch indicator is added to the solution.
A blue-black color appears when starch indicator is added to the solution.
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To prepare a sodium thiosulfate solution, a burette must be filled with potassium iodate solution.
To prepare a sodium thiosulfate solution, a burette must be filled with potassium iodate solution.
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The end-point of the titration is indicated by a color change from colorless to blue-black.
The end-point of the titration is indicated by a color change from colorless to blue-black.
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The average titration figure was 27.45 cm^3.
The average titration figure was 27.45 cm^3.
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Excess potassium iodide was used to ensure that all the iodine was kept in solution.
Excess potassium iodide was used to ensure that all the iodine was kept in solution.
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One tablet weighs 0.24 grams.
One tablet weighs 0.24 grams.
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The average volume of sodium thiosulfate required in the titration was 25 cm^3.
The average volume of sodium thiosulfate required in the titration was 25 cm^3.
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Starch was used as an indicator in the titration, resulting in a color change from blue to colorless at the end point.
Starch was used as an indicator in the titration, resulting in a color change from blue to colorless at the end point.
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The concentration of sodium hypochlorite in the original bleach solution is 0.644 moles per litre.
The concentration of sodium hypochlorite in the original bleach solution is 0.644 moles per litre.
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The molecular mass of sodium hypochlorite (NaClO) is approximately 74.5 g/mol.
The molecular mass of sodium hypochlorite (NaClO) is approximately 74.5 g/mol.
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The reaction between iodine and thiosulfate produces disulfite ions.
The reaction between iodine and thiosulfate produces disulfite ions.
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In the experiment, the solution in the volumetric flask should be diluted before titration.
In the experiment, the solution in the volumetric flask should be diluted before titration.
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The starch indicator is added at the beginning of the titration.
The starch indicator is added at the beginning of the titration.
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Potassium iodide is added to the conical flask to produce iodine during the experiment.
Potassium iodide is added to the conical flask to produce iodine during the experiment.
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Sodium thiosulfate reacts with iodine in a 1:2 molar ratio.
Sodium thiosulfate reacts with iodine in a 1:2 molar ratio.
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Dilute sulfuric acid is used to neutralize the bleach solution.
Dilute sulfuric acid is used to neutralize the bleach solution.
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The endpoint of the titration is indicated by a blue-black color in the solution.
The endpoint of the titration is indicated by a blue-black color in the solution.
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The concentration of sodium hypochlorite in household bleach can be determined using titration.
The concentration of sodium hypochlorite in household bleach can be determined using titration.
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Study Notes
Volumetric Analysis: Oxidation-Reduction
- Volumetric analysis is used to determine the concentration of oxidizing and reducing agents.
- Potassium permanganate (KMnO4) is a key oxidizing agent.
- Potassium permanganate is a purple solid, but not a primary standard due to purity issues.
- It needs standardization via titration against a primary standard.
- In acidic solutions, KMnO4 acts as an oxidizing agent, gaining 5 electrons.
- MnO4- + 8H+ + 5e- → Mn2+ + 4H2O
- Potassium permanganate acts as its own indicator.
- To undergo the reaction, dilute acid is added to provide H+ ions.
- The concentration of KMnO4 solution can be determined by titrating it against a solution containing Fe2+ ions. KMnO4 converts Fe2+ to Fe3+.
- Oxidizing agent: MnO4-
- Reducing agent: Fe2+
- 5 Fe2+ ions react with 1 MnO4- ion.
- MnO4- + 8H+ + 5Fe2+ → Mn2+ + 5Fe3+ + 4H2O
- Ammonium iron(II) sulfate (FeSO4) provides Fe2+ ions for titration. It's a primary standard since it is pure and unaffected by air.
Mandatory Experiment: Standard Solution Preparation
- Procedure to prepare a standard ammonium iron(II) sulfate solution and use it to standardize a KMnO4 solution.
- Rinse glassware (pipette, burette, conical flask) with deionized water.
- Rinse the burette with KMnO4 solution, pipette with Fe2+ solution.
- Fill pipette with Fe2+ solution, transfer to conical flask. Acidify with sulfuric acid (H2SO4).
- Fill burette with KMnO4 solution, ensuring the lower part is full before adjusting to zero.
- Add KMnO4 dropwise while swirling, noting the first permanent pale pink colour and the burette reading.
- Repeat the process to get two consistent titre values to within 0.1 cm3.
Solving Volumetric Problems in Redox Reactions
- Formulas for calculating molarity and volumes of oxidizing and reducing agents.
- Example of calculating concentration of KMnO4 solution using titration titrations.
- Note that one mole of MnO4- reacts with 5 moles of Fe2+.
Mandatory Experiment: Determining Iron in Tablets
- Procedure to determine the amount of iron (Fe) in an iron tablet.
- Weigh five tablets.
- Crush the tablets, dissolve them in diluted sulfuric acid, and transfer all the solution to a 250 cm3 volumetric flask filling up to the mark using deionized water; wash the flask to ensure all the tablet contents are in the flask.
- Rinse pipette and burette with potassium permanganate (KMnO4) and iron(II) solutions respectively.
- Fill the pipette with iron solution and transfer to a conical flask. Acidify with sulfuric acid.
- Fill the burette with potassium permanganate.
- Add the KMnO4 solution dropwise to the conical flask while swirling until the first permanent pale pink colour appears and note the burette reading; avoid excess.
- Repeat the process to obtain two consistent titre readings, adjusting to within 0.1 cm3.
- Calculate the iron concentration and the mass of iron in the tablet.
Mandatory Experiment: Sodium Thiosulfate Standardization
- Procedure for preparing a sodium thiosulfate (Na2S2O3) solution and standardizing it using iodine (I2) titrations.
- Rinse glassware with deionized water. Rinse the pipette with potassium iodate and the burette with sodium thiosulfate.
- Fill the pipette with potassium iodate and add to the conical flask.
- Add sulfuric acid and potassium iodide to the conical flask.
- Fill the burette with sodium thiosulfate.
- Titrate by adding sodium thiosulfate, using starch as an indicator until the solution turns colourless.
- Note the burette reading.
- Repeat to get consistent titre values within 0.1cm3.
- Calculate the concentration of the thiosulfate solution.
Mandatory Experiment: Bleach Analysis
- Procedure to determine the percentage of sodium hypochlorite (NaClO) in a bleach solution.
- Dilute the bleach solution
- Rinse glassware
- Add potassium iodide and sulfuric acid to generate iodine (I2).
- Titrate the iodine solution with sodium thiosulfate (Na2S2O3) solution, using starch as an indicator, until the solution turns colourless.
- Note the burette reading
- Repeat the process to ensure that the titre is within 0.1cm3.
- Calculate the concentration of sodium hypochlorite (NaClO).
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Description
This quiz explores the principles of volumetric analysis, focusing on oxidation-reduction reactions. Learn how potassium permanganate is used as an oxidizing agent and how to determine its concentration through titration with Fe2+ ions. Test your understanding of the chemical equations and processes involved in this analysis.
