Your email address will not be published. Completing the CAPTCHA proves you are a human and gives you temporary access to the web property. For example, chloromethane, CH3CI, is composed of the methyl group, CH3-, (obtained from methane, CH4, by the loss of a hydrogen atom) linked to the substituent chlorine atom. Meaning of Homologous Series. The table below shows the relationship between the parent alkane, alkyl group and their formula. All compounds having the same carbon framework (skeleton) and the same functional group in their molecules possess similar properties. This series is certainly an important topic within the field of organic chemistry. The numerous organic compounds can be grouped into a comparatively small number of series or families of compounds known as homologous series. Organic compounds belonging to the main class can be divided into different families, known as homologous series, on the basis of similarity in structure and chemical properties. The formula of various homologues can be written by giving the values 1, 2, 3, 4, ….. to n. (iii) The molecular mass of every two adjacent members differs by 14 (CH2 = 12 + 2 x 1 = 14). A functional group is an atom, a radical (group of atoms) or a bond common to a homologous series, and which determines the main chemical properties of the series. Explanations of Prevost Theory of Heat Radiation, TechPrep : Another Free Facebook Site for Programmers, 18 Amazing Facts on Earth’s Perfect Location in Space, Carcinogenic Effects of Chewing Betel Nut, Emergency? The homologous series derived from alkanes. You may need to download version 2.0 now from the Chrome Web Store. Performance & security by Cloudflare, Please complete the security check to access. General Methods of Preparation: All members can usually be prepared by using the same general methods, e.g., alkanes can be prepared by the action of hot soda lime on the appropriate sodium salt of an acid. A homologous series (homos is Greek for “the same as”) can be defined as the group of compounds in which the various members have similar structural features and similar chemical properties and the successive members differ in their molecular formula by one methylene (CH2) group. If you are on a personal connection, like at home, you can run an anti-virus scan on your device to make sure it is not infected with malware. Similarly, the melting points and densities of the alkanes also increase, while their solubility in water decreases down the series. Currently you have JavaScript disabled. The alkyl groups derived from the first six members of the parent alkane series. Tony is an Avid Tech enthusiast that loves Scientific Inventions and Tech Products. Your email address will not be published. For example, the boiling points of the alkanes increase down the series, so that the first four members are gases at room temperature and standard pressure; members with five to seventeen carbon atoms per molecule are volatile liquids; while the higher members are wax-like solids. General Molecular Formula: All members share a general molecular formula, i.e., CnH2n + 2 for the alkanes, CnH2n for the alkenes, and so on. For example, the boiling points of the alkanes increase down the series, so that the first four members are gases at room temperature and standard pressure; members with five to seventeen carbon atoms per molecule are … (iv) All compounds in the series have similar chemical properties because of the presence of the same functional group. Organic compounds belonging to the main class can be divided into different families, known as homologous series, on the basis of similarity in structure and chemical properties. Other homologous series include the alkenes, CnH2n, the alkanols, CnH2n+1 OH, and the carboxylic acids, CnH2n+1 COOH. Your IP: 5.9.117.98 The functional group determines the basic chemistry of a compound, while the alkyl group affects the physical properties of a compound. For example, the polar hydroxyl group in the alkanols promotes solubility in water but the non-polar alkyl group opposes it. They burn in air, forming carbon(IV) oxide and water, and undergo substitution reactions with other substances such as halogens. Effect of the Alkyl and Functional Groups. Cloudflare Ray ID: 5f86e7ee4949178a For example, the polar hydroxyl group in the, on "Significance and Properties of the Homologous Series", Electronic Configuration and Properties of the Tra…, Electronic Configuration and Properties of the Transition Elements, Activity Series and the Significance of Hydrogen, Extraction and Uses of the Lanthanide Elements. The univalent group which is formed from an alkane by the loss of a hydrogen atom is known as the alkyl group. All compounds having the same carbon framework (skeleton) and the same functional group in their molecules possess similar properties. Click here for instructions on how to enable JavaScript in your browser. Such a family of compounds is known as a homologous series and each individual member is referred to as a homologue. From the table below, we see that each individual member of the alkane series differs from the preceding or the following member by one carbon atom and two hydrogen atoms, i.e. The simplest series of compounds in organic chemistry is the alkanes. Hey Edubuzzer, welcome to the learning platform, EDUBUZZ NOTES. In order to post comments, please make sure JavaScript and Cookies are enabled, and reload the page. The general characteristics of a homologous series are: (i) All compounds in the series are composed of the same elements and contain the same functional group. Properties of Homologous Series. each functional group has its own characteristic properties. These groups are referred to as the functional groups, e.g., the hydroxyl group, -OH, the amino group, -NH2, the carboxyl group, -COOH, and the double covalently bonded carbon atoms, C=C. Thus, the compound that is formed by substitution can be considered as being made up of the alkyl group and the substituent group. When two or more functional groups occur in one molecule, the properties of one are often modified or influenced by the presence of the others. The general term alkyl group includes all groups derived from the alkanes by the loss of a hydrogen atom. You Are Here: The chemical reactivity of an alkyl compound is determined mainly by the substituent group. (vi) The homologues can be prepared by almost similar methods. Another way to prevent getting this page in the future is to use Privacy Pass. • The alkanes are a series of hydrocarbons with a general molecular formula of CnH2n + 2, where n is a whole number with a value of one or more. Some important series of aliphatic compounds are listed below: If we examine the unbranched alkanes, we notice that each alkane differs from the preceding alkane by one —CH2— group. A homologous series is a family of organic compounds which follows a regular structural pattern, in which each successive member differs in its molecular formula by a –CH2 – group. Homologous series have the following common characteristics. Chemical Properties: The members show similar chemical properties. Thus, the presence of the functional group or groups determines the chemical, properties of a homologous series. –CI. Such compounds when arranged in order of their molecular masses constitute a series called homologous series and the individual members are called homologues. He blogs Passionately on Science and Technology related niches and spends most of his time on Research in Content Management and SEO. Such organic compounds that vary from one another by a repeating unit and have the same general formula form a series of compounds. Alkyl groups have a general formula of CnH2n+1. Click here for instructions on how to enable JavaScript in your browser.