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Md. Istiqur Rahman
ID: 111-29-269
L2 T2
Dept. of Pharmacy
Daffodil International University
Pharmaceutical Analysis
Pharmaceutical analysis may be defined as a process or
sequences of processes to identify and/or q...
Titration
Titration, also known as titrimetry, is a common
laboratory method of quantitative chemical
analysis that is use...
Redox Titration
 Redox titrations are based on a reduction-oxidation
reaction between an oxidizing agent and a reducing a...
Oxidizing Agent
An oxidizing agent (also called
an oxidant, oxidizer or oxidiser) can be defined as a
substance that remov...
Potassium Permanganate
 Potassium permanganate is an inorganic chemical
compound with the formula KMnO4. It is
a salt con...
Why potassium
permanganate is
stronger
oxidizing agent
compared to other
Because it contains Manganese in its highest
oxidation state of +7.
This compound is a strong oxidizing agent
because el...
 Potassium permanganate oxidizes
aldehydes to carboxylic acids, such as the
conversion of n-heptanal to heptanoic acid:
5...
Potassium Dichromate
Potassium dichromate, K2Cr2O7, is a
common inorganic chemical reagent, most
commonly used as an oxidi...
 In organic chemistry, potassium dichromate is a mild
oxidizer compared with potassium permanganate.
 It is used to oxid...
Comparison Between -
Potassium Dichromate
&
Potassium Permanganate
ξ Both are powerful oxidants, but typically if one can use
manganate you do so with preference over chromate.
Chromate is ...
ξ Potassium dichromate is carcinogenic and should be
handled with gloves and appropriate health and safety
protection; per...
Potassium permanganate, potassium dichromate – one of the excellent tools of analysis
Potassium permanganate, potassium dichromate – one of the excellent tools of analysis
Potassium permanganate, potassium dichromate – one of the excellent tools of analysis
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Potassium permanganate, potassium dichromate – one of the excellent tools of analysis

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Potassium permanganate, potassium dichromate – one of the excellent tools of analysis

  1. 1. Md. Istiqur Rahman ID: 111-29-269 L2 T2 Dept. of Pharmacy Daffodil International University
  2. 2. Pharmaceutical Analysis Pharmaceutical analysis may be defined as a process or sequences of processes to identify and/or quantify a substance or drug, the components of a pharmaceutical solution or mixture or the determination of the structures of chemical compounds used in the formulation of pharmaceutical product.
  3. 3. Titration Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Because volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant or titrator is prepared as a standard solution. A known concentration and volume of titrant reacts with a solution of analyte or titrand to determine concentration.
  4. 4. Redox Titration  Redox titrations are based on a reduction-oxidation reaction between an oxidizing agent and a reducing agent. A potentiometer or a redox indicator is usually used to determine the endpoint of the titration, as when one of the constituents is the oxidizing agent potassium dichromate. The color change of the solution from orange to green is not definite; therefore an indicator such as sodium diphenylamine is used.  Some redox titrations do not require an indicator, due to the intense color of the constituents. For instance, in permanganometry a slight faint persisting pink color signals the endpoint of the titration because of the color of the excess oxidizing agent potassium permanganate.
  5. 5. Oxidizing Agent An oxidizing agent (also called an oxidant, oxidizer or oxidiser) can be defined as a substance that removes electrons from another reactant in a redox chemical reaction. The oxidizing agent is "reduced" by taking electrons onto itself and the reactant is "oxidized" by having its electrons taken away. Oxygen is the prime example of an oxidizing agent, but it is only one among many – 1. KMnO4 (potassium permanganate) 2. K2Cr2O7 (potassium dichromate) 3. O3 (ozone) 4. F2 (fluorine)
  6. 6. Potassium Permanganate  Potassium permanganate is an inorganic chemical compound with the formula KMnO4. It is a salt consisting of K+ and MnO4 − ions. Formerly known as permanganate of potash or Condy's crystals, it is a strong oxidizing agent. It dissolves in water to give intensely purple solutions.  Potassium permanganate can be used to quantitatively determine the total oxidizable organic material in an aqueous sample. The value determined is known as the permanganate value. In analytical chemistry, a standardized aqueous solution of KMnO4 is sometimes used as an oxidizing titrant for redox titrations (permanganometry).  For the standardization of KMnO4 solutions, reduction by oxalic is often used.
  7. 7. Why potassium permanganate is stronger oxidizing agent compared to other
  8. 8. Because it contains Manganese in its highest oxidation state of +7. This compound is a strong oxidizing agent because elements become more electronegative as the oxidation states of their atoms increase. The permanganate in potassium permanganate has the anion MnO4- that is the reason for its strong oxidizing properties. KMnO4, being a very strong oxidizing agent, can react with a variety of groups.
  9. 9.  Potassium permanganate oxidizes aldehydes to carboxylic acids, such as the conversion of n-heptanal to heptanoic acid: 5 C6H13CHO + 2 KMnO4 + 3 H2SO4 → 5 C6H13COOH + 3 H2O + K2SO4 + 2 MnSO4  Even an alkyl group (with a benzylic hydrogen) on an aromatic ring is oxidized, e.g. toluene to benzoic acid. 5 C6H5CH3 + 6 KMnO4 + 9 H2SO4 → 5 C6H5COOH + 14 H2O + 2 K2SO4 + 6 MnSO4
  10. 10. Potassium Dichromate Potassium dichromate, K2Cr2O7, is a common inorganic chemical reagent, most commonly used as an oxidizing agent in various laboratory and industrial applications. It is a crystalline ionic solid with a very bright, red-orange color. It is also known as potassium bichromate; bichromate of potash etc.
  11. 11.  In organic chemistry, potassium dichromate is a mild oxidizer compared with potassium permanganate.  It is used to oxidize alcohols. It converts primary alcohols into aldehydes, or into carboxylic acids if heated under reflux.  In contrast, with permanganate, carboxylic acids are the sole products. Secondary alcohols are converted into ketones — no further oxidation is possible.  For example, menthone may be prepared by oxidation of menthol with acidified dichromate. Tertiary alcohols are not oxidized by potassium dichromate.
  12. 12. Comparison Between - Potassium Dichromate & Potassium Permanganate
  13. 13. ξ Both are powerful oxidants, but typically if one can use manganate you do so with preference over chromate. Chromate is dangerously toxic stuff. ξ Dichromate is +6 oxidation state, and this rapidly converts to chromate +5 which is one of the most powerful inorganic carcinogens. On the other hand, manganese is not that bad. ξ Unlikely to Potassium Permanganate, Potassium Dichromate is acutely and chronically harmful to health and must be handled and disposed of appropriately.
  14. 14. ξ Potassium dichromate is carcinogenic and should be handled with gloves and appropriate health and safety protection; permanganate is not carcinogenic. ξ Unlikely to Potassium Permanganate, Potassium Dichromate is corrosive and exposure may produce severe eye damage or blindness. Human exposure further encompasses impaired fertility, heritable genetic damage and harm to unborn children. ξ As an oxidizer, potassium permanganate is stronger than potassium dichromate.

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