Carbon chains of varying length have been observed in organic compounds having the same general formula. Homologous series cie igcse chemistry revision notes. Wmpjan11chem1 12 do not write outside the box 12 6 octane is the eighth member of the alkane homologous series. The functional group of aldehyde is aldehydic group i. A homologous series is a group of chemicals which have similar chemical properties and can be represented by a general formula. They differ in formula from one member to the next by one ch2 unit.
A homologous series is a family of organic compounds containing a particular characteristic group and exhibiting similar properties. A series of a organic compound each containing a characteristic functional group and the successive members differ by from each other in molecular formula by ch2methylene group is called homologous series. Alkanes, alkenes, alcohols, carboxylic acids and esters belong to different homologous series. Such series are most common among organic compounds, the structural difference being a methylene group, as in the paraffin hydrocarbons, or. Introduction the word homologous series and functional groups describe a few of the umbrella principles that assist in the understanding of organic compounds in spite of their large number. What is the homologous series of hydrocarbons what do you mean by homologous series. Homologous series homologous series characteristics chemistry 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 optical band gaps were determined by uvvis and fluorescence spectroscopy in solution. Each member differs from successive member by ch 2. Alkanes form a homologous series and so do alkenes. T he numerous organic compounds can be grouped into a comparatively small number of series or families of compounds known as homologous series. Common functional groups and their families of compound.
A homologous series is a group or family of organic compounds that has certain characteristics. A series of organic compounds that have similar structural features but differ from adjacent members by ch 2 group is referred to as homologous series. Lahvanya raoov moved describe the general characteristics of an. Homologous series grade 11 science notes reference notes. Homologous series organic compounds are grouped into different homologous series. The characteristics of a homologous series is the study of the compounds of carbon in organic chemistry. Members have the almost same chemical properties due to same functional group. What are the general characteristics of a homologous series. Homologous series are not unique to organic chemistry. The following is one of the chemistry spm 2009 questions related to homologous series. Describe the general characteristics of an homologous series. This can be the length of a carbon chain, for example in the straightchained alkanes paraffins, or it could be the number of monomers in a homopolymer such as amylose. In the field of organic chemistry, a homologous series is a series of compounds with the same functional group and similar chemical properties in which the members of the series can be branched or unbranched. Alkenes are more reactive than alkanes and react with bromine water, turning it from.
Most of the homologous series are abundant in organic chemistry, but it is not unique only to organic chemistry. Difference in molecular mass of two consecutive members of the series is 14 unit i. Alkane, alkene, alcohol, carboxylic acids and esters. Characteristics of a homologous series k12 education.
A homologous series is a series of carbon compounds that have different numbers of carbon atoms but contain the same functional group. Homologous series are referenced frequently in organic chemistry, where compounds can. For example, the compounds given below belong to the alcohol family. Oct 10, 2014 this article gives an explanation for the homologous series and their characteristics. Currentvoltage characteristics of a homologous series of. We shall study this series to illustrate what a homologous series means. A group of organic compounds containing same functional group which can be represented by the same general formula and which have similar trends in their properties are called a homologous series. Based on the table, state and explain five characteristics of a homologous series. Two adjacent members of homologous series differ by ch2 online chemistry tutorial iit, cbse chemistry, icse chemistry, engineering and medical chemistry entrance exams, chemistry viva, chemistry job interviews. Jan 10, 2018 characteristics of a homologous series. All the members of a series can be represented by same general formula.
Present general information about the definition, characteristics and structure of homologous including additional information not found in the original video lesson include at least 2 facts not. The first four members of the homologous series of alkenes are ethene, propene, butene and pentene. It is atom or group of atoms or reactive part of compound which largely determines the chemical properties of compound, e. Homologous series are referenced frequently in organic chemistry, where compounds can differ by the length of their carbon chain. State any four characteristics of a homologous series. Significance and properties of the homologous series. 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 ch 2 group characteristics of homologous series. Homologous series chemistry, class 11, organic chemistry.
A series of organic compounds that have similar structural features but differ. All the members of a homologous series have same chemical properties due to. In chemistry, a homologous series is a group of compounds that share the same basic chemical makeup, but differ in the number of iterations of a certain aspect of their structure. In first year organic chemistry, the first ten names of the homologous series are usually all that need to be memorized. Jul 27, 2015 deltastep is a social initiative by graduates of iimahmedabad, iimbangalore, iitkharagpur, isikolkata, columbia university usa, ntu singapore and other leading institutes. The simplest series of compounds in organic chemistry is the alkanes. The number of carbons continuously bonded together is an important structural feature and is described using the homologous series. Naming branched chain alkanes homologous series national. Natures chemistry hydrocarbons and homologous series. Tutorials for chemistry learning functional groups and homologous series functional groups. Homologous series is a series of compounds with similar chemical properties and same functional group differing from the successive member by ch 2. Ch 3 oh methyl alcohol methanol ch 3 ch 2 ch 2 oh propyl alcohol. Dec 04, 2018 the first four members of the homologous series of alkenes are ethene, propene, butene and pentene.
Jun 10, 2018 there will be a gradation in the physical and chemical properties. They show a steady change in physical properties from one member to the next. The sheer scale of organic chemistry means that it is important to categorise compounds with similarities in order to make sense of the vast number of organic compounds possible. Homologous series homologous series characteristics. Homologous seriesfunctional groups and isomerism, chemistry tutorial. The table below shows the first four alcohols in the alcohol homologous series. Jan 10, 20 the characteristics of a homologous series is the study of the compounds of carbon in organic chemistry. Significance and properties of the homologous series gulpmatrix.
Lahvanya raoov moved describe the general characteristics of an homologous series lower. Homologous series are families of organic compounds. It describes what are called a homologous series, examples of these series, and properties of some of selected homologous series in detail. This video is created by more videos and free notes are available at. In chemistry, a homologous series is a series of organic compounds with a similar general formula, possessing similar chemical properties due to the presence of the same functional group, and. A homologous series is a family of hydrocarbons with similar chemical properties who share the same general formula. The general characteristics of a homologous series are. Characteristics of homologous series carbon compound youtube. Each member of homologous series is called homolog. It is a series of compounds which are derived from same general formula, having same functional group, similar chemical properties and show gradation in physical properties. The organisation of organic compounds into the various different homologous series makes the study of organic chemistry more systematic, orderly and effective.
Write any 4 characteristic features of homologous series of organic compounds. Difference in molecular mass of two consecutive members of the series is 14. Homologous series is defined as a systematic order of organic compounds having same functional group that can be represented by same general formula and prepared by same method. A homologous series in organic chemistry is a group of organic compounds compounds that contain c atoms that differ from each other by one methylene ch2. The alkanes, alkenes and cycloalkanes are examples of homologous series. This is a series or family of organic compounds that have similar features and chemical properties due to them having the same functional group. Nov 01, 2019 homologous series khan academy, homologous series in hindi, homologous series class 11, homologous series igcse, homologous series in urdu, homologous series in organic chemistry, homologous.
What are the characteristics of homologous series answers. The members of the homologous series have same functional group. In the field of organic chemistry, a homologous series is a series of compounds with the same functional group and similar chemical properties in which the. The carbon atoms have a unique property to combine with other carbon atoms repeatedly. A homologous series in organic chemistry is a group of organic compounds compounds that contain c atoms that differ from each other by one methylene ch 2 group. The difference between two consecutive members in their composition is ch 2 unit.
For example, methane, ethane, propane, butane, etc. Describe characteristics of homologous series qs study. Alkenes are more reactive than alkanes and react with bromine water, turning it from orange to colourless the general formula for the homologous series of alkenes is cnh2n alkenes are hydrocarbons with a double carboncarbon bond. The functional group of alcohols is the hydroxyl group i. For example, methane, ethane, and propane are part of a homologous series. Natures chemistry homologous series national 5 chemistry. What are the physical and chemical properties of homologous. Alcohols in the homologous series can be regarded as alkanes in which one hydrogen atom is replaced by a hydroxyl group. Categorisation relies on similarities between and within structures, giving rise to the concept of homologous series. The table shows some information about three members of a homologous series. Order in homologous series photograph shows the first members of various homologous series.
In chemistry spm, students were introduced with five homologous series. Write any 4 characteristic features of homologous series of. Also each member of the series will be having an increase in mass no. The characteristics of a homologous series is outlined below. When an atom or group of atoms bonded to a carbon atom in the chain or ring of an organic compound, shown some characteristic properties of their own, they are termed as a functional group. Homologous series is defined as a systematic order of organic compounds having same. All members of a series contain the same functional group i. Homologous series, any of numerous groups of chemical compounds in each of which the difference between successive members is a simple structural unit. A homologue also spelled as homolog is a compound belonging to a series of compounds differing from each other by a repeating unit, such as a methylene bridge. They are named by replacing the final e in the corresponding alkane by ol. A homologous series in organic chemistry is a group of organic compounds compounds that contain carbon c atoms that diverge from each other by one methylene ch 2 group.
Such series are most common among organic compounds, the structural difference being a methylene group. In chemistry, homology is the appearance of homologues. Deltastep is a social initiative by graduates of iimahmedabad, iimbangalore, iitkharagpur, isikolkata, columbia university usa, ntu singapore and other leading institutes. The physical and chemical properties of the series will show a continuous gradation. Aug 20, 2018 what is the homologous series of hydrocarbons what do you mean by homologous series.
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