Quantitative analysis
Quantitative analysis : 1. Estimation of Carbon and Hydrogen: Both carbon and hydrogen are estimated together in one operation. A known mass of the organic substance is burnt in excess of oxygen when the carbon and hydrogen present in it are oxidised to carbon dioxide and water respectively. The mass of and thus formed are determined and the percentage of carbon and hydrogen is calculated. The method is known as Liebig’s combustion method. Apparatus: The apparatus used consists of three...
read moreQualitative analysis
Qualitative analysis: After purifying an organic compound, the first step in establishing its composition is to ascertain the nature of the elements present in it. The order of abundance in which these elements are present in organic compounds is indicated below: Element Order of abundance Carbon Always...
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Chromatography Chromatography is an analytical technique employed for the purification and separation of organic and inorganic substances. It is also very helpful for the fractionation of complex mixtures, separation of closely related compounds such as isomers, homologues as well as in the isolation of unstable compounds. In this technique the compounds are recovered without any change or alteration. Classification: Chromatography can be classified into following types: (1) Paper Chromatography (2) Column Chromatography (3) ...
read moreCriteria of Purity of a Substance
Criteria of Purity of a Substance The melting point and boiling point of a substance indicates the purity of a substance. Every pure compound has a definite melting point or boiling point. If the substance melts at lower temperature or boils at a higher temperature then it is impure. The impurities depress the melting point and elevate the boiling point. Melting Point: The pure solid substance melts sharply at a definite temperature while as impure substance will have a lower and indefinite melting point. In the laboratory it is...
read morePurification of Organic Compounds
Purification of Organic Compounds Most of the organic substances when synthetically prepared or isolated from natural source are impure due to the presence of some bye-products or reactants. Before the compound can be analysed qualitatively or quantitatively, it is necessary that it should be in a pure state. Purification is not always easy and various methods depending upon the nature of the compound and impurities are employed. The following methods are generally used for this purpose: (1) Crystallization (2) Fractional...
read moreNomenclature of Bicylo Compounds
Nomenclature of Bicylo Compounds A class of saturated compounds consisting of two rings only, having two or more atoms in common, containing at least one hetero atom, and that take the name of an open chain hydrocarbon containing the same total number of atoms. In Bicyclo compounds two rings are fused together at two C-atoms known, as Bridged head C-atoms. We name compounds containing 2 fused or bridged rings as bicyclo alkanes and we use the name of the alkane corresponding to the total number of carbon atoms as the base name. The carbon...
read moreSpiro Compounds
Spiro Compounds A spiro compound is a bicyclic organic compound with rings connected through just one atom. The rings can be different in nature or identical. The connecting atom is also called the spiroatom, most often a quaternary carbon (“spiro carbon”). All spiro compounds have the infix spiro followed by square brackets containing the number of atoms in the smaller ring and the number of atoms in the larger ring excluding the spiroatom itself; the numbers being separated by a dot. For example compound A is called...
read moreNaming of Stock Line Notations
Naming of stock line notations Here one point is considered as one C-atom while
read moreAmine
Amine Amines are organic compounds that contain nitrogen and are basic. The general form of an amine is shown in Lewis form. R represents an alkyl group, but either or both of the hydrogens may be replaced by other groups and still retain its class as an amine.The fact that amines tend to have foul odors is emphasized by the names of two amines: cadaverine and putresine. Amines are alkyl or aryl derivatives of . These are of three types. (primary-amine), (a) Primary Amines: these are named as amino alkane or...
read moreCyanide
Cyanide A cyanide is a chemical compound that contains the cyano group, , which consists of a carbon atom triple-bonded to a nitrogen atom. Cyanides most commonly refer to salts of the anion CN?. Most cyanides are highly toxic. Organic compounds containing (cyanide) are named by three systems. (a) Cyanide system: In this system they are named as if they are the salts of hydrogen cyanide (HCN). (b) Common system: Their common names derived from the common names of the acids to which they are hydrolysed . The ending -ic...
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