what is permanganometric titration

Full Answer

What is the difference between titration and permanganometry?

The titration involves volumetric manipulations to prepare the analyte solutions. Permanganometry allows the detection and estimation of the quantitative presence of various chemical species, such as iron (II), manganese (II), oxalate, nitrite, and hydrogen peroxide .

What is permanganometry in chemistry?

Permanganometry is one of the techniques used in quantitative analysis in chemistry. It is a redox titration and involves the use of permanganates and is used to measure the amount of analyte present in unknown chemical samples.

What is the ratio of hydrogen peroxide to permanganate for titration?

According to the reaction equation given above 1 mole of permanganate reacts with 2.5 mole of hydrogen peroxide and this ratio have to be used for titration result calculation.

What is the concentration of solubility of solid permanganate?

Solid permanganate is difficult to prepare in form pure enough to be used as standard substance, so it is not possible to prepare its solution of known concentration just by dissolving known mass of solid. Commonly used solutions are 0.02M (0.1 normal).

What is meant by Permanganometric titration?

Permanganometry is one of the techniques used in chemical quantitative analysis. It is a redox titration that involves the use of permanganates to measure the amount of analyte present in unknown chemical samples.

What is the role of KMnO4 in titration?

KMnO4 acts as an indicator of where the permanganate ions are a deep purple colour. In this redox titration, MnO4– is reduced to colourless manganous ions (Mn2+) in the acidic medium. The last drop of permanganate gives a light pink colour on reaching the endpoint.

What type of reaction is involved in Permanganometric titration?

Hint: Permanganometric titrations are redox titrations in which Potassium permanganate is the oxidant and reductant. Complete step by step answer: A chemical reaction which involves both oxidation and reduction is known as Redox reaction.

Which acid is used in Permanganometric titration?

dilute sulphuric acidTo determine the concentration/molarity of KMnO4 solution by titrating it against a 0.1 M standard solution of oxalic acid. The acid used in this titration is dilute sulphuric acid.

Why is KMnO4 a suitable indicator?

Potassium Permanganate is a flexible and potent oxidant which can be used by overt or indirect titration to classify many compounds. A special value of Potassium Permanganate is that it acts as an indicator of its own. Permanganate titration must be carried out in a heavy acid solution.

Is KMnO4 basic or acidic?

Potassium permanganate is a strong oxidizing agent in acid medium, but is a weak oxidant in the neutral and alkaline medium.

What is the end point in Permanganometric titration?

During permanganate tirtrations such as titration of potassium permanganate with oxalic acid, oxalic acid solution is in a conical flask and potassium permanganate solution is in the burette. As the end point is reached, the solution changes colour to pink as potassium permanganate has intense purple colour.

What is the role of H2SO4 in Permanganometric titration?

H2SO4 increase the acidic content of the solution so as to prevent MnO4 (purple) to reduced to MnO2(dark brow). Hence sulfuric acid is stable in the present of strong oxidising agent. If HCl acid is use it will be oxidised to Cl and make the end point much higher.

Why kmno4 is used in burette?

2 Answers. The reason for this is because kmno4 is a coloured substance and as well as a self indicator,while mohr`s salt is colourless and an indicator can be used to get an accurate end point. But if kmno4 is taken in conical flask,it wolud be very difficult to observw the reaction completion.

Why only Sulphuric acid is used in titration?

Titrations with Permanganate must be carried out in strong acid solution. Sulfuric Acid is generally used for this purpose because Nitric Acid and Hydrochloric Acid can participate in competing oxidation-reduction reactions, reducing the accuracy of the titration.

Why do we use Sulphuric acid?

Uses of Sulphuric Acid Sulphuric acid is highly acidic. Therefore, it is used in the cleaning of metals, removal of impurities from oil, manufacturing of chemicals – nitric acid, hydrochloric acid, synthesis of dye, drugs, detergents, explosives, etc.

Why is Sulphuric acid added to potassium dichromate?

Sulfur dioxide react with potassium dichromate and sulfuric acid to produce potassium sulfate, chromium(III) sulfate and water and the solution turns from orange to green.

general remarks

Hydrogen peroxide is usually treated as a strong oxidizer, but in the presence of even stronger oxidizer it can become a reducing agent:

sample size

For 0.02 M titrant and assuming 50 mL burette, aliquot taken for titration should contain about 0.060-0.077 g of hydrogen peroxide (1.7-2.3 millimoles).

end point detection

As usual in the case of permanganate titrations, pink color of excess permanganate is strong enough so that there is no need for any other end point indicators.

solutions used

To perform titration we will need titrant - 0.02 M potassium permanganate solution, concentrated sulfuric acid (diluted 1:4) and some amount of distilled water to dilute hydrogen peroxide sample.

procedure

Pipette aliquot of hydrogen peroxide solution into 500mL Erlenmeyer flask.

result calculation

According to the reaction equation given above 1 mole of permanganate reacts with 2.5 mole of hydrogen peroxide and this ratio have to be used for titration result calculation.

sources of errors

Apart from general sources of titration errors, when titrating hydrogen peroxide we should pay special attention to titrant. Potassium permanganate solutions are not stable and they should be filtered and normalized every 2-3 months.

Principle

This method utilizes the reduction of potassium permanganate (KMnO4) by hydrogen peroxide in sulfuric acid.

Scope of Application

This method is suitable for measuring aqueous solutions of H2O2 ranging from 0.25 to 70 wt.%.

Interferences

Any substance which reduces KMnO4 under acidic conditions will produce a positive interference.

Safety Precautions

Please consult Safety and Handling guidelines (see here), particularly as relates to personal protective clothing and footware. Neoprene or PVC aprons are recommended, as are monogoggles and neoprene rubber gloves. Sample bottles containing H2O2 should not be stoppered, but rather vented or covered loosely with aluminum foil or paraffin film.

Procedure

From the table below, transfer an appropriate aliquot of H2O2 sample to a tared weighing bottle and weigh on an analytical balance.

What is the solution used for iron titration?

Reinhardt-Zimmermann solution is used for iron titration. It combines concentrated sulfuric acid (necessary to lower pH to the values at which permanganate is a strong oxidizer, besides acid is consumed during the reaction), phospohric acid (used to complex iron (III) - complex is colorless and doesn't interfere with the end point detection) and manganese (II) sulfate (added to lower redox potential of permanganate so that the side reaction of oxidization of chlorides to free chlorine is eliminated).

How long to boil permanganate?

Once permanganate is dissolved it should be boiled for about an hour, to oxidize organic contaminants that can be present in the solution.

Is potassium permanganate a solid?

Potassium permanganate solution. Solid permanganate is difficult to prepare in form pure enough to be used as standard substance, so it is not possible to prepare its solution of known concentration just by dissolving known mass of solid. Commonly used solutions are 0.02M (0.1 normal).

What is the formula for lanthanum strontium manganite?

Lanthanum strontium manganite, La 1-x Sr x MnO 3, belongs to an extensive group of rare-earth manganites with the general formula Re 1-x A x MnO 3, where Re is the rare-earth ion (La, Nd, Pr) and A is a divalent ion (Ca, Sr, Ba). The rare-earth manganites are nowadays the subject of extensive research because of their promising electrical and magnetic properties and a great variety of usage [ 1 ]. For example, they can be used in magnetic refrigerators due to the magneto-caloric effect (adiabatic temperature change of a magnetic material associated with an external magnetic field change). Furthermore, due to the high electrical conductivity, chemical and high-temperature stability, rare-earth manganites can also be used as cathode materials in solid oxide fuel cells (SOFC) and for thermochemical energy storage (TCES) applications [ [2], [3], [4] ].

Why are oxygen rich perovskites needed for SOFC?

On the other hand, oxygen-poor perovskites are necessary for SOFC applications because oxygen vacancies contribute to higher electrical and ionic conductivity [ 10, 11 ].

Can manganite be used as a cathode?

Furthermore, due to the high electrical conductivity, chemical and high-temperature stability, rare-earth manganites can also be used as cathode materials in solid oxide fuel cells (SOFC) and for thermochemical energy storage (TCES) applications [ [2], [3], [4] ].

Is manganite an oxidation state?

It is established that the electrical and magnetic properties of manganites are closely related to the Mn oxidation state, which is determined by the oxygen content of the sample . Many of 3d transition metal oxides possess a strong tendency for oxygen nonstoichiometry, depending on the preparation method [ 5 ].

General Remarks

Permanganometry is one of the techniques used in chemical quantitative analysis. It is a redox titration that involves the use of permanganates to measure the amount of analyte present in unknown chemical samples. It involves two steps, namely the titration of the analyte with potassium permanganate solution and then the standardization of potassium permanganate solution with standard sodium oxalate solution. The titration involves volumetric manipulations t…

Sample Size

End Point Detection

Solutions Used

Procedure

Result Calculation

Sources of Errors

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