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. Successive members differ from each other by c h 2. This series has enabled scientists and engineers to study different organic compounds in a systematic manner. It describes what are called a homologous series, examples of these series, and properties of some of selected homologous series in detail.
The homologous series has compound with the same general formula and functional group all the compounds of the series have same chemical properties and physical properties with a gradual variation. Significance and properties of the homologous series. They can predict the properties of organic compounds belonging to a particular homologous series based on the data available from the other members of the same series. Characteristics of homologous series carbon compound. An homologous series is a group of compounds with similar structural features that can be represented by a general formula whose members differ by one ch 2 unit you can think of an homologous series as a family or group of compounds, whose chemical behaviour is very similar and whose physical properties show trends when ascending the members of the group in terms of. Such series are most common among organic compounds, the structural difference being a methylene group, as in the paraffin hydrocarbons, or alkanes.
Describe characteristics of homologous series qs study. Describe the concept of homologous series as a family of similar compounds with similar chemical properties due to the presence of the same. Wmpjan11chem1 12 do not write outside the box 12 6 octane is the eighth member of the alkane homologous series. What are the general characteristics of a homologous series. Jan 23, 2016 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. Alcohols are hydrocarbon compounds containing one or more hydroxyl group o h attached to a saturated carbon atom. Homologous series are families of organic compounds.
Homologous series are referenced frequently in organic chemistry, where compounds can. Homologous series grade 11 science notes reference notes. Most of the homologous series are abundant in organic chemistry, but it is not unique only to organic chemistry. All members of a homologous series contain the same elements and functional group. Homologous series organic compounds are grouped into different homologous series.
The successive members vary from each other by a ch 2 unit. Characteristics of homologous series each member of the series differs from the preceding or succeeding member by one methylene group ch 2 and hence by a molecular mass of 14 amu. The organisation of organic compounds into the various different homologous series makes the study of organic chemistry more systematic, orderly and effective. The alcohols which only contain one hydroxyl group attached to a saturated carbon form a homologous series. The compounds in a homologous series should have 1 similar chemical formulas 2 similar chemical properties 3 physical properties that show a gradual change or trend based on the differences in their formulas for example, you could look at boiling points of h2o, h2s, and h2se and then explain the difference with a discussion of intermolecular. Carbon chains of varying length have been observed in organic compounds having the same general formula. For example, you could look at boiling points of h2o, h2s, and h2se and then explain the difference with a discussion of.
The same thing can be observed in case of alkenes in which the first member is ethene and the successive members are c 3 h 6, c 4 h. 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. Introduction to chemistry class 11 unacademy jee iit jee chemistry paaras sir unacademy jee 1,920 watching live now. The table shows some information about three members of a homologous series. Alkanes form a homologous series and so do alkenes. A homologous series is a family of hydrocarbons with similar chemical properties who share the same general formula. Homologous series of alkanes, alkenes and alkynes with.
Ways to identify homologous series are discussed as well as the chemical and physical properties of. A homologous series is a group or family of organic compounds that has certain characteristics. A homologous series is a group of chemicals which have similar chemical properties and can be represented by a general formula. For example, methane, ethane, and propane are part of a homologous series. Homologous series are not unique to organic chemistry. Significance and properties of the homologous series gulpmatrix. In first year organic chemistry, the first ten names of the homologous series are usually all that need to be memorized.
They show a steady change in physical properties from one member to the next. 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. The functional group of alcohols is the hydroxyl group i. Homologous series definition in the cambridge english. 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. Homologous series definition a homologous series is a group of organic chemical compounds, usually listed in order of increasing size, that have a similar structure and hence, also similar properties and whose structures differ only by the number of c h 2 units in the main carbon chain. All members of a series contain the same functional group i. Properties of homologous series definition, examples, diagrams. Aug 20, 2018 what is the homologous series of hydrocarbons what do you mean by homologous series. What are the physical and chemical properties of homologous.
A hydrocarbon homologous series is a series of hydrocarbons which. 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. In organic chemistry, a homologous series is a series of compounds with the same functional group. A homologous series is a group of chemicals which have similar chemical. Two consecutive members of a homologous series differs each. So, if the functional group doesnt change, why are homologous series interesting. Based on the table, state and explain five characteristics of a homologous series. Ch3och3, c2h5och3, c3h7och3 are the members of homologous series called ethers. Alkanes, alkenes, alcohols, carboxylic acids and esters belong to different homologous series.
Natures chemistry homologous series national 5 chemistry. Homologous series chemistry britannica encyclopedia britannica. 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. For example, methane, ethane, propane, butane, etc. 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. A homologous series is a series of carbon compounds that have different numbers of carbon atoms but contain the same functional group. They differ in formula from one member to the next by one ch2 unit. Difference in molecular mass of two consecutive members of the series is 14 unit i. Characteristics of homologous series carbon compound youtube.
A homologous series is a group of organic compounds, which has the same functional group, but two successive members differ by ch 2 group. Jan 10, 2018 characteristics of a homologous series. Differ by ch 2 in molecular formulae from neighbouring compounds. Characteristics of a homologous series k12 education. Dec 02, 2018 this video is created by more videos and free notes are available at.
Homologous series, any of numerous groups of chemical compounds in each of which the difference between successive members is a simple structural unit. The number of carbons continuously bonded together is an important structural feature and is described using the homologous series. 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. Due to the presence of the same functional group, compounds within the same homologous series have similar chemical properties. The alkanes, alkenes and cycloalkanes are examples of homologous series. Also each member of the series will be having an increase in mass no. State any four characteristics of a homologous series. 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. All members of a homologous series exhibit some common characteristics. Homologous series meaning in the cambridge english. Order in homologous series photograph shows the first members of various homologous series. All the members of a series can be represented by same general formula. Such series are most common among organic compounds, the structural difference being a methylene group, as in the paraffin hydrocarbons, or. The simplest series of compounds in organic chemistry is the alkanes.
Homologous series is a series of compounds with similar chemical properties and same functional group differing from the successive member by ch 2. T he numerous organic compounds can be grouped into a comparatively small number of series or families of compounds known as 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. The following is one of the chemistry spm 2009 questions related to homologous series. Naming branched chain alkanes homologous series national. The members of a series have same functional group. The characteristics of a homologous series is the study of the compounds of carbon in organic chemistry. Choose from 352 different sets of homologous series flashcards on quizlet. For example in ch 4 and c 2 h 6, the difference is ch 2 unit and the difference between c 2 h 6 and c 3 h 8 is also ch 2 unit. The physical and chemical properties of the series will show a continuous gradation. Homologous series meaning in the cambridge english dictionary. 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.
Oct 10, 2014 this article gives an explanation for the homologous series and their characteristics. Homologous series cie igcse chemistry revision notes. 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. This lesson covers the definition of a homologous series of molecules in organic chemistry. The carbon atoms have a unique property to combine with other carbon atoms repeatedly. All the members of a homologous series can be represented by a common general formula, as they have the same functional group. Detailed revision notes on the topic homologous series. Homologous series are referenced frequently in organic chemistry, where compounds can differ by the length of their carbon chain. Physical properties change regularly with increasing number of carbon atoms. General characteristics of members of homologous series definition members of the series can be represented by a general formula. Such a family of compounds is known as a homologous. Jan 10, 20 the characteristics of a homologous series is the study of the compounds of carbon in organic chemistry. All the members of the same series cant be represented by the 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.
Homologous series homologous series characteristics. Principle cetyl alcohol is as palmitic acid ester the major component of spermaceti. Describe the general characteristics of a homologous series. Homologous series of alkanes, alkenes and alkynes with examples. The general characteristics of a homologous series are. The functional group of aldehyde is aldehydic group i. 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.
Titanium, vanadium, and molybdenum oxides all form homologous series e. Homologous series, in chemistry can be defined as a series of organic compounds with a similar general formula, possessing similar chemical properties due to. Properties of homologous series definition, examples. What are the characteristics of homologous series answers. Notes on homologous series grade 10 science carbon. We shall study this series to illustrate what a homologous series means.
Homologous series, any of numerous groups of chemical compounds in each of which the difference between successive members is a simple. Learn homologous series with free interactive flashcards. 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. Within a given homologous series the chemical properties of the compounds are essentially all alike, and the physical properties vary in a.
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