Biography & Contributions
Viktor Meyer was a German chemist born on September 08, 1848 – died on August 08, 1897. Meyer was well known chemist for his great discoveries like Viktor Meyer apparatus, thiophene heterocyclic compound.
While working on of methods to determining the vapour densities of inorganic substances at high temperatures, Meyer found that diatomic molecules of iodine and bromine dissociate into atoms upon heating.
In 1872 he discovered the aliphatic nitro compounds. He was the first person to coin the term stereochemistry. He also coined the term steric hindrance concept in chemistry.
Meyer discovered the oximes and demonstrated their stereoisomerism. Later in the year 1882 he discovered thiophene chemical compound – a compound which is similar to benzene’s chemical and physical properties.
Oxime
Oxime, any of a class of nitrogen-containing organic compounds usually prepared from hydroxylamine and an aldehyde, a ketone, or a quinone. Oximes are usually generated by the reaction of hydroxylamine and aldehydes or ketones. The condensation of aldehydes with hydroxylamine gives aldoxime, and ketoxime is produced from ketones and hydroxylamine. Oximes can also be made by the action of hydrogen-donating reagents upon certain nitro compounds or by the isomerization of nitroso compounds. Oxime compounds are used as antidotes for nerve agents, as artificial sweetener etc.
Thiophene
Thiophene is an aromatic, heterocyclic flat five-membered ring. Thiophene was discovered as a contaminant in benzene. It was observed that isatin forms a blue dye if it is mixed with sulfuric acid and crude benzene. Thiophene and its derivatives occur in petroleum, sometimes in concentrations up to 1–3%. Thiophenes are important heterocyclic compounds that are widely used as building blocks in many agrochemicals and pharmaceuticals.
Viktor Meyer Apparatus
Viktor Meyer apparatus is the standard laboratory method for determining the molecular weight of a volatile liquid.
The liquid in the outer jacket section of viktor meyer apparatus, is heated until spent air escapes from the side tube. Then, a graduated tube filled with water is inverted over the side tube dipping in a trough filled with water. A small quantity of substance is weighed exactly in a small stoppered bottle and is dropped in the Victor Meyer's tube and sealed immediately.
The bottle falls on the asbestos pad and its contents suddenly change into vapour, and then blow out the stopper followed by displacing an equal volume of air in graduated tube. The volume of air displaced is measured by taking the graduated tube out, closing its mouth with thumb and dipping in a jar filled with water. When water levels inside and outside the tube will become equal, the volume of air displaced is noted. The atmospheric pressure and laboratory temperature are noted.
No comments:
Post a Comment