The simplest series of compounds in organic chemistry is the alkanes. May 21, 2019 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 group. Feb 27, 2019 homologous structures are similar structures in related organisms. The alkanes, alkenes and cycloalkanes are examples of homologous series. The successive members vary from each other by a ch 2 unit. Learn homologous series with free interactive flashcards. Each homologous series must have the following four characteristics. Homologous series of alkanes, alkenes and alkynes with examples. The members of this series are called homologue and differ from each other by the number of ch 2 units in the main carbon chain. Whereas homologous structures point to a similar origin and a common ancestor, analogous structures are when animals have similar structures with similar function, but they evolved separately.
The individual members of a homologous series are known as homologous and the process is. Choose from 352 different sets of homologous series flashcards on quizlet. For example, methane, ethane, propane, butane, etc. The difference between each member of an homologous series is one ch 2 unit. Examples of functional groups, homologous series, general formula, displayed formula, graphic formula, molecular formula, skeletal formula, structural formula, empirical formula of molecules etc. A homologous series is a series of carbon compounds that have different numbers of carbon atoms but contain the same functional group. A series of compounds in which successive members differ from one another by a ch 2 unit is called a homologous series.
Organic compounds also have functional groups, which define the basic properties of the compound. Organic compounds consequently tend to be less soluble as an homologous series is ascended. Any two adjacent homologues differ by ch 2 in their molecular formulae all the compounds of a homologous series show similar chemical properties. Carbon chains of varying length have been observed in organic compounds having the same general formula. Homologous series meaning in the cambridge english dictionary. Nov 16, 2017 difference between position isomerism and metamerism definition position isomerism. Homologous series is a series of compounds with similar chemical properties and same functional group differing from the successive member by ch 2. All the compounds of a homologous series show similar chemical properties. Jan 25, 2020 a translocation mutation is a type of mutation in which a piece of one chromosome breaks off and is joined to another chromosome. 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. Following are the characteristics of a homologous series. 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. T he numerous organic compounds can be grouped into a comparatively small number of series or families of compounds known as homologous series.
Deletion, the loss of genetic material, and duplication, the. All the members of homologous series of alkynes have similar structure and similar chemical properties, so they can be grouped together into the homologous series. Notes on functional group and homologous series grade 11. Explain why the combustion of wood rather than coal can reduce the effect of the emissions. In a homologous series there is a gradual increase in boiling point as the number of carbon atoms increases. Covalent bonds are formed when atoms share pair of electrons. A homologous series is a group of chemicals which have similar chemical properties and can be represented by a general formula. A human karyotype shows the complete set of human chromosomes. Thus, a functional group is an atom or group of atoms which determine the chemical behavior of an. Homologous series and its characteristics with examples. Predict and explain the trends in boiling points of members of a homologous series. The most important part, as hinted by their name, is that they are structurally similar. Homologous series is a series of organic compounds where the successive members follow a regular pattern. A homologous series is a family of organic compounds containing a particular characteristic group and exhibiting similar properties.
Give three characteristics which all members of a homologous series. Such organic compounds that vary from one another by a repeating unit and have the same. 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. In other words, only organisms that are somehow related to each other can have homologous structures. Give three characteristics which all members of a homologous series share. During sexual reproduction, one chromosome in each homologous pair is donated from the mother and the other from the father. The individual members of a homologous series are called homologues and the phenomenon is called homology. All the members of a homologous series can be represented by a general formula. Such series are most common among organic compounds, the structural difference being a methylene group, as in the paraffin hydrocarbons, or alkanes.
Chemicals in the same homologous series will show a gradual variation in one property eg. Jul 02, 20 a homologous series is a series of compounds with a similar general formula, usually varying by a single parameter such as the length of a carbon chain. Homologous structures definition and examples biology. In that series, successive members differ in mass by an extramethylene bridgech 2 unit inserted in the chain. What is homologous series explain with an example science. In organic chemistry, a homologous series is a series of compounds with the same general formula, usually varying by a single parameter. Homologous series definition of homologous series by. A series of organic compounds in which hydrogen in a carbon chain is replaced by the same functional group, is called homologous series. 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. Common examples of homologous structures are the bones in the forelimbs of various vertebrates, such as humans, dogs, birds and. The same thing can be observed in case of alkenes in which the first member is ethene and the successive members. Any two adjacent homologues differ by ch 2 in their molecular formulae all the compounds of a.
Translocation mutation between non homologous chromosomes is not to be confused with crossover between homologous chromosomes or regions of chromosomes. Common functional groups and their families of compound. 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. Homologous seriesfunctional groups and isomerism, chemistry tutorial. In biology, homology is similarity due to shared ancestry between a pair of structures or genes in different taxa. Thus themolecular massof each member differs by 14atomic massunits.
The homologous series of straightchained alkanes begins withmethanech 4,ethanec 2 h 6,propanec 3 h 8,butanec 4 h 10, andpentanec 5 h 12. Homologous series are referenced frequently in organic chemistry, where compounds can differ by the length of their carbon chain. 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. Compounds within a homologous series typically have a fixed set of functional groups that gives them similar chemical and physical properties. Homologous series a homologous series is a group of compounds with similar characteristics and the same general formula. Each human cells contain 23 pairs of chromosomes or 46 total. Homologous series meaning in the cambridge english. A homologous series is a group of organic compounds having similar structure and similar chemical properties in which the successive compound differs by ch2 group for example. Covalent bonds are formed when atoms share pair of. 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. This means that the compounds are identical with the exception of the number of ch2 units in the compound.
Significance and properties of the homologous series. A series of compounds with similar chemical properties, in which members differ from one another by the possession of an additional ch2 group, is called a homologous series. Homologous series of alkanes, alkenes and alkynes with. For example, a chimpanzees arm and a humans arm are homologous structures. 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 group. Position isomerism is the presence of a similar carbon skeleton and functional groups in two or more organic compounds, but the location of the functional groups is different from each other. An insect population lives along the edge of a northsouth mountain range. Difference between position isomerism and metamerism. It is important that you commit to memory the names of the first 10 straightchain alkanes i. Hydrocarbons are chain molecules of varying lengths made from hydrogen and carbon atoms only, joined together by covalent bonds. 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.
Cambridge international examinations cambridge international. Nov 14, 2016 homologous structures are organs or skeletal elements of animals and organisms that, by virtue of their similarity, suggest their connection to a common ancestor. For example, the compounds given below belong to the alcohol family. Difference between position isomerism and metamerism definition position isomerism. Such series are most common among organic compounds, the structural difference being a methylene group, as in the paraffin hydrocarbons, or. A homologous series is a series of compounds, which has the same functional group. Examples of such series are the straightchained alkanes paraffins, and some of their derivatives such as the primary alcohols, aldehydes, and monocarboxylic acids.
When organic compounds containing same functional group are arranged in series on the basis of their increasing molecular weight, having the difference of ch 2 methylene group in between two consecutive compounds, such series is called homologous series. Examples include the wings on butterflies, bats, and birds. This video is a part of the series for cbse class 10, chemistry demo videos for chapter carbon and its compounds. Ch 3 oh methyl alcohol methanol ch 3 ch 2 ch 2 oh propyl alcohol. Since there is a change in the physical properties, we can say that there would be an increase in the molecular size and mass. Most of the hydrocarbons in crude oil are hydrocarbons called alkanes. The populations from the east and west slope eventually join in a low northern pass and interbreed, producing fertile offspring, but they do not circle around the southern edge because of a desert barrier. 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. These structures do not have to look exactly the same, or have the same function. This means that they have similar chemical properties to each other and they have trends in. Every chromosome pair represents a set of homologous chromosomes.
A common example of homologous structures is the forelimbs of vertebrates, where the wings of bats and birds, the arms of primates, the front flippers of whales and the forelegs of fourlegged vertebrates like dogs and crocodiles are all derived from the same ancestral tetrapod. All members of a homologous series exhibit some common characteristics. The ch 2 group is nonpolar hydrophobic and this increases the percentage of the molecule that is unattractive to water. This means that they have similar chemical properties to each other and they have trends in physical properties. Functional groups and homologous series functional groups. A homologous series is a series of organic compounds which belong to the same family i. The alkanes are a homologous series of hydrocarbons. Homologous series, any of numerous groups of chemical compounds in each of which the difference between successive members is a simple structural unit. A homologous series is a series of compounds with the same general formula, usually varying by a single parameter such as the length of a carbon chain. This video is a part of the series for cbse class 10, chemistry demo videos for chapter carbon and its. All the members of a homologous series can be represented by a common general formula, as they have the same functional group. Information and translations of homologous series in the most comprehensive dictionary definitions resource on the web. This also contains similar general formula and chemical properties.
Homologous seriesfunctional groups and isomerism, chemistry. For example, methane, ethane, and propane are part of a homologous series. For example, the alkane group contains the ch2 repeating unit. Organic functional groups homologous series explained why. In that series, successive members differ in mass by an extra methylene bridge ch 2 unit inserted in the chain.
971 1343 974 1496 1124 1174 677 440 1454 59 974 1478 416 862 909 712 1451 868 1038 1140 917 1368 1104 122 1410 845 86 290 433