Tag: chemistry

Purification of Organic Compounds

Organic compounds are compounds that contain carbon atoms covalently bonded to hydrogen atoms, and may also contain other elements such as nitrogen, oxygen, sulfur, and halogens. These compounds are found in nature and are also synthesized in laboratories for various purposes. However, these compounds may contain impurities that affect their properties and functions, making it necessary to purify them before use.


Source – Wikipedia

Purification of organic compounds involves the removal of impurities by various methods such as filtration, distillation, chromatography, and crystallization. The choice of method depends on the nature of the impurities, the physical properties of the compound, and the desired purity level.

  • Filtration is a method used to separate insoluble impurities from a liquid or solid. It involves passing the mixture through a filter paper or membrane to remove the impurities. This method is effective for large particles and non-volatile impurities, but it is not suitable for removing dissolved impurities.
  • Distillation is a method used to separate volatile liquids or liquids with different boiling points. It involves heating the mixture to vaporize the more volatile component and condensing it back into a liquid, leaving behind the less volatile component. This method is effective for separating liquids with a significant difference in boiling points, but it may not be effective for separating liquids with close boiling points or non-volatile impurities.
  • Chromatography is a method used to separate and purify a mixture of components based on their different affinities to a stationary phase and a mobile phase. It involves passing the mixture through a column or plate containing the stationary phase, and the components are separated based on their different retention times or distances. This method is effective for separating components with similar physical properties, and it can achieve high levels of purity.
  • Crystallization is a method used to purify a solid by dissolving it in a solvent and allowing it to recrystallize under controlled conditions. Impurities are excluded from the growing crystal lattice, resulting in a purer product. This method is effective for purifying solids with high melting points and for removing impurities that have different solubility than the desired compound.

In addition to these methods, other techniques such as sublimation, extraction, and reflux can also be used to purify organic compounds. Sublimation involves the conversion of a solid to a gas without passing through the liquid state, and it is effective for purifying solids with high vapor pressures. Extraction involves the separation of a compound from a mixture by selectively dissolving it in a solvent, and it is effective for separating compounds with different polarities. Reflux involves heating a mixture under controlled conditions to allow for the separation and purification of volatile components.

Overall, the purification of organic compounds is a critical step in many chemical processes and requires careful consideration of the nature of the impurities and the physical properties of the compound. By using appropriate methods and techniques, it is possible to achieve high levels of purity and obtain compounds that are suitable for various applications in industry, medicine, and research.

The Marie Effect

Maria Salomea Sktodowska was born on 7 November 1867 in Warsaw , Poland. She was the 5th child born to father Vladislav and Mother Bronislava sklodowska , who were both teachers. Because of bad investments, the family lost its savings and had to move to a private school where her mother taught.

Maria started her schooling in 1874, and she was the youngest and the smartest in her class. During that time, Warsaw was under Russian rule which banned polish dictums. Russian government forbade any polish women to attend university of Warsaw. So Marie and her older sister Bronya ,would pool their finances so that first her older sister ( Bronya ) could complete her education, and then Marie could attend University of Paris. Manya ( as Maria was also called) spent 6 years as governess and taught peasant children how to read and write.

She also attended secret meetings of “Floating University ” where they read scientific studies. By 1891,she had collected enough money to continue her studies in Paris. She moved there and lived with her sister and her husband and changed her name to Marie. She attended the Sorbonne University and then later moved to the student area , a tiny attic sized housing. In 1893,she earned her master’s degree in Physics, and then studied Mathematics on a scholarship.During this, she also got a job to study magnetism properties of various types of steel for French company.

She later met Pierre Curie and they got married in 1895 , and gave birth to daughter Irene the following year.

Later she decided to make French physicist Henri Becquerel and his discovery of mysterious Uranium rays in 1896 as her topic of physics doctorate. She began studying Uranium type rays radiated from other elements and found that Thorium also gave out such rays. Most of Uranium type rays given off by rocks called pitchblende- gave more radiation than she expected.

She announced in July,1898 that she found a new element and named it POLONIUM , after Poland and also invented the word ‘ radioactive ‘ , and later she also founded Radium.

To prove that she had indeed found those new elements, she had to produce pure radium. And finally on 21 july 1902 she reported the weight of 1 radium atom. In 1903, she became the first woman in Europe to receive doctorate in science. Radium began to be used for treating cancer cells, and the new treatment began to be called ‘ Curie treatment’. Marie and Pierre were awarded the Humphry Davy medal ; England’s highest award in chemistry.

The same year , she and her husband ,along with Henri Becquerel , were awarded the Nobel Prize in Physics .In 1906, Pierre died by falling off horse drawn wagon.

In 1911, Marie won Nobel Prize in chemistry for her work in radioactivity.

She died in 1934 of aplastic anaemia due to prolonged exposure to radiation .

Later, in 1935,Irene and her husband Fredrick, were awarded the Nobel Prize in chemistry .