Learn homologous series with free interactive flashcards. 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. Homologous series are referenced frequently in organic chemistry, where compounds can differ by the length of their carbon chain. Chemical reactions can either go in both directions forward and reverse or only in one direction. 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. What are the general characteristics of a homologous series. Jan 10, 20 the characteristics of a homologous series is the study of the compounds of carbon in organic chemistry. The ones that go in two directions are known as reversible reactions, and you can identify them by the arrows going in two directions, like the exa. The difference in molecular mass of two consecutive members. Usually these compounds vary by a single parameter such as the length of a carbon chain. Characteristics of homologous series 1 all compounds in the series are composed of same elements and contain the same functional group. Such a family of compounds is known as a homologous. All members of a homologous series contain the same elements and functional group.
Members of the same homologous series can be prepared through one common method. Homologous series is a series of compounds with similar chemical properties and same functional group differing from the successive member by ch 2. 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 members of a homologous series have similar chemical properties. The alkanes, alkenes and cycloalkanes are examples of homologous series. Characteristics of a homologous series general formula. This lesson covers the definition of a homologous series of molecules in organic chemistry. Carbon chains of varying length have been observed in organic compounds having the same general formula. A homologation reaction is a chemical process that converts one member of a homologous series to the next member.
For the love of physics walter lewin may 16, 2011 duration. 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 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. So, if the functional group doesnt change, why are homologous series interesting. Homologous series, any of numerous groups of chemical compounds in each of which the difference between successive members is a simple structural unit.
Examples of such series are the straightchained alkanes paraffins, and some of their derivatives such as the primary alcohols, aldehydes, and monocarboxylic acids. All the families of organic compounds exist as a homologous series a series having a difference of ch2 unit between two consecutive members the main homologous serieses are alkanes, alkenes. Significance and properties of the homologous series. 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. In chemistry, a homologous series is a series of chemical compounds with the same general formula. Lahvanya raoov moved describe the general characteristics of an homologous series lower. The most important of the organic anhydrides is acetic anhydride. If we examine the unbranched alkanes, we notice that each alkane differs from the preceding alkane by one ch 2 group. Some important classes of organic molecules are derivatives of alkanes, such as the primary alcohols, aldehydes, and monocarboxylic. The ancestor of tetrapods evolved four limbs, and its descendents have inherited that feature so the presence of. Within a given homologous series the chemical properties of the compounds are essentially. The domestication syndrome is a collection of desirable characteristics associated with the domestication of crops from their wild progenitors 35,38.
Aroma properties of a homologous series of 2,3epoxyalkanals and trans4,5epoxyalk2enals. Functional groups and homologous series sneak peek. 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. What are the characteristics of homologous series answers. Deltastep is a social initiative by graduates of iimahmedabad, iimbangalore, iitkharagpur, isikolkata, columbia university usa, ntu singapore and other leading institutes.
Weve made some important changes to our privacy and cookies policy and we. This video is created by more videos and free notes are available at. For example, methane, ethane, propane, butane, etc. Homologous series homologous series characteristics. Notes on functional group and homologous series grade 11. Therefore, the members of the homologous series shows a change in the physical properties with increase in the molecular mass. The ancestor of tetrapods evolved four limbs, and its descendents have inherited that feature so the presence of four limbs is a homology.
All the members of a series can be represented by the same general formula. Chemicals in the same homologous series will show a gradual variation in one property eg. The number of carbons continuously bonded together is an important structural feature and is described using the homologous series. Natures chemistry homologous series national 5 chemistry. Alcohols are hydrocarbon compounds containing one or more hydroxyl group o h attached to a saturated carbon atom. The successive members vary from each other by a ch 2 unit. All the families of organic compounds exist as a homologous series a series having a difference of ch2 unit between two consecutive members the main homologous series es are alkanes, alkenes.
The characteristics of a homologous series is the study of the compounds of carbon in organic chemistry. Homologous series of alkanes, alkenes and alkynes with examples. Such series are most common among organic compounds, the structural difference being a methylene group, as in the paraffin hydrocarbons, or. The members of the homologous series have same functional group. The simplest acyclic alkynes with only one triple bond and no other functional groups form a homologous series with the general chemical formula c n h 2n. One homologous chromosome is inherited from the organisms mother. 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. They also carry genes that determine individual traits that can be inherited through reproduction. A series of compounds with similar chemical properties, in which members differ from one another by additional ch2 group, is called a homologous series. Lahvanya raoov moved describe the general characteristics of an homologous series from to do. 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.
Birds, bats, mice, and crocodiles all have four limbs. Why homologous series of carbon compounds are so called. Characteristics of a homologous series k12 education. What are the important characteristics of multiple allele. 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.
The homologous series of straightchained alkanes begins methane ch 4, ethane c 2 h 6, propane c 3 h 8, butane c 4 h 10, and pentane c 5 h 12. Categorisation relies on similarities between and within structures, giving rise to the concept of homologous series. We shall study this series to illustrate what a homologous series means. 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. Catalytic properties of the homologous series of the. 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. Homologous series are referenced frequently in organic chemistry, where compounds can. Homologous series of alkanes, alkenes and alkynes with. What are the characteristics of dynamic equilibrium. 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. For example, you could look at boiling points of h2o, h2s, and h2se and then explain the difference with a discussion of. Any two adjacent members of a homologous series differ by a ch2 unit in.
The members of a series have same functional group. So humans have two homologous chromosome sets in each cell, meaning humans are diploid organisms. The alcohols which only contain one hydroxyl group attached to a saturated carbon form a homologous series. Aroma properties of a homologous series of 2,3epoxyalkanals and.
Some important classes of organic molecules are derivatives of alkanes, such as the primary alcohols, aldehydes, and mono carboxylic. A homologous series is a series of carbon compounds that have different numbers of carbon atoms but contain the same functional group. Sep 20, 2019 chemical reactions can either go in both directions forward and reverse or only in one direction. Members have the almost same chemical properties due to same functional group. Compounds within a homologous series typically have a fixed set of functional groups that gives them similar chemical and physical properties. All the organic compounds have been divided into different families or group depending upon their structure and chemical properties. 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.
Ch3och3, c2h5och3, c3h7och3 are the members of homologous series called ethers. 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. 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. Homologous series chemistry, class 11, organic chemistry. 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. Choose from 352 different sets of homologous series flashcards on quizlet. Apr 18, 2010 other than sharing the same general formula, what are 2 other features of members of the same homologous series. Describe the general characteristics of an homologous series.
Homologous series grade 11 science notes reference notes. Jun 10, 2018 there will be a gradation in the physical and chemical properties. In first year organic chemistry, the first ten names of the homologous series are usually all that need to be memorized. In organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carboncarbon triple bond. Each member of homologous series is called homolog. Significance and properties of the homologous series gulpmatrix. 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. 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 is a group or a class of organic compounds having same general formula and similar chemical properties in which the successive members differ by a ch 2 group let us consider members of alkanes given in table 11. T he numerous organic compounds can be grouped into a comparatively small number of series or families of compounds known as homologous series. A hydrocarbon homologous series is a series of hydrocarbons which. The table below shows the first four alcohols in the alcohol homologous series. Chromosomes are important molecules because they contain dna and genetic instructions for the direction of all cell activity.
An extinct animal named tiktaalik was an important discovery by scientists because it had characteristics of both. With one methodology all the compound of the series can be. An example of homologous characters is the four limbs of tetrapods. Two consecutive members of a homologous series differs each. A pair of homologous chromosomes contains chromosomes of similar length, gene position, and centromere location. 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 a homologous series is a group of compounds with similar characteristics and the same general formula.
Some examples of homologous series are shown in the following table. Legumes are important members of nearly all agricultural systems, as well as one of the most. Some important series of aliphatic compounds are listed below. State any four characteristics of a homologous series. The 22 pairs of homologous chromosomes contain the same genes but code for different traits in their allelic forms since one was inherited from the mother and one from the father. Multiple alleles is a series of three or more alternative forms of same gene occupying a single locus on the chromosome, e. The general characteristics of a homologous series are. The physical and chemical properties of the series will show a continuous gradation.
There are a number of homologous series in organic compounds. Multiple alleles are always at the same location locus in the chromosome. Lahvanya raoov moved describe the general characteristics of an. Homologous series examples, answers, activities, experiment. Also each member of the series will be having an increase in mass no. 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 the preparation method of the compounds present in the series remains the same. 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. Such organic compounds that vary from one another by a repeating unit and have the same general formula form a series of compounds. A series of compounds having similar structural formulae, same functional group and hence similar chemical properties are called homologous series of compounds. Characteristics of homologous series carbon compound youtube. Ways to identify homologous series are discussed as well as the chemical and physical properties of. Each member differs from successive member by ch 2. They are named by replacing the final e in the corresponding alkane by ol. Other than sharing the same general formula, what are 2 other features of members of the same homologous series.
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