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. A hydrocarbon homologous series is a series of hydrocarbons which. The carbon atoms have a unique property to combine with other carbon atoms repeatedly. The alkanes family is a homologous family which have linear molecules. The characteristics of a homologous series is outlined below. Homologous series examples, answers, activities, experiment. The general characteristics of a homologous series are. 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.
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. Describe characteristics of homologous series qs study. Characteristics of a homologous series general formula. 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. The name homologous series is also often used for any collection of compounds that have similar structures or include the same functional group, such as the general alkanes straight and branched, the alkenes olefins, the carbohydrates, etc. Homologous series organic compounds are grouped into different homologous series.
However, if the members cannot be arranged in a linear order by a single parameter, the collection. Ways to identify homologous series are discussed as well as the chemical and physical properties of 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. Chemicals in the same homologous series will show a gradual variation in one property eg. There will be a gradation in the physical and chemical properties. Homologous series a homologous series is a group of compounds with similar characteristics and the same general formula. Such organic compounds that vary from one another by a repeating unit and have the same. The physical and chemical properties of the series will show a continuous gradation. A series of organic compounds that have similar structural features but differ from. All members of a series contain the same functional group i.
Notes on functional group and homologous series grade 11. Characteristics of homologous series 1 all compounds in the series are composed of same elements and contain the same functional group. A homologous series is a family of hydrocarbons with similar chemical properties who share the same general formula. This lesson covers the definition of a homologous series of molecules in organic. What are the general characteristics of a homologous series. The functional group of alcohols is the hydroxyl group i. A general formula of the characteristics of a homologous series is capable of representing infinite number of homologous but only a small number of compounds belonging to each. All the members of a series can be represented by same general formula. Homologous series of alkanes, alkenes and alkynes with. 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. What is the homologous series of hydrocarbons what do you mean by homologous series.
Properties of homologous series definition, examples. Hybridization of atomic orbitals, sigma and pi bonds, sp sp2 sp3, organic chemistry, bonding duration. Due to the presence of the same functional group, compounds within the same homologous series have similar chemical properties. Alkanes form a homologous series and so do alkenes. Homologous series, general formula, repeating unit, functional groups. Within a given homologous series the chemical 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. Characteristics of homologous series carbon compound youtube. The difference between two consecutive members in their composition is ch 2 unit. The difference in molecular mass of two consecutive members.
Carbon chains of varying length have been observed in organic compounds having the same general formula. Homologous series are families of organic compounds. Learn homologous series with free interactive flashcards. Jun 22, 2018 mathematical tables are super interesting. Homologous series are referenced frequently in organic chemistry, where compounds can. The trend within any homologous series is of decreasing solubility as the hydrophobic chain length increases. The following is one of the chemistry spm 2009 questions related to homologous series. In first year organic chemistry, the first ten names of the homologous series are usually all that need to be memorized.
Also each member of the series will be having an increase in mass no. Homologous series have the following common characteristics. Alcohols r oh, aldehydes r cho, carboxylic acid r cooh, ketonesrcor are some of homologous series and their general formulae. A homologation reaction is a chemical process that converts one member of a homologous series to the next member. Jun 10, 2018 there will be a gradation in the physical and chemical properties. All compounds in homologous series have functional group except alkanes. Such series are most common among organic compounds, the structural. For example, methane, ethane, and propane are part of a homologous series.
All members of a homologous series exhibit some common characteristics. The compounds are named as for the alkanes, but with the ending, ene instead of ane. In organic chemistry, a homologous series is a series of compounds with the same functional group. Aug 20, 2018 what is the homologous series of hydrocarbons what do you mean by homologous series. Homologous series meaning in the cambridge english. 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. Two consecutive members of a homologous series differs each other in their composition by ch 2. Such series are most common among organic compounds, the structural difference being a methylene group, as in the paraffin hydrocarbons, or. Homologous series cie igcse chemistry revision notes.
Which type of bond occurs in a saturated hydrocarbon molecule. Because alkenes are hydrocarbons with at least one carboncarbon double bond the alkene homologous series starts at ethene c 2 h 4. The general formula for the homologous series of alkenes is c n h 2n where n is the number of carbon atoms. A homologous series is a group of chemicals which have similar chemical properties and can be represented by a general formula. This is true unless the molecules are very small and polar, or can form hydrogen bonds with the water molecules. Oct 15, 2019 characteristics of a homologous series are. Homologous series chemistry, class 11, organic chemistry. By how many carbon atoms does each member of a homologous series differ from the previous member. In which group could the hydrocarbons all belong to the same homologous series. Homologous series grade 11 science notes reference notes. 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. Is the special group of atoms available in homologous series compounds which is responsible for the chemical properties of the compound. Alkane, alkene, alcohol, carboxylic acids and esters. In the general formula of compounds of a homologous series, the symbol r is used to represent its functional group.
In general which property do organic compounds share. Members of a homologous series can be represented by a general formula. Homologous series is a series of compounds with similar chemical properties and same functional group differing from the successive member by ch 2. The members of a series have same functional group. Based on the table, state and explain five characteristics of a homologous series. Lahvanya raoov moved describe the general characteristics of an homologous series from to do. Gce study buddy the best o level revision resource. The first four alkanes in the homologous series retain their original names. Alcohols are hydrocarbon compounds containing one or more hydroxyl group o h attached to a saturated carbon atom. Characteristics of a homologous series k12 education. A homologous series is a group or family of organic compounds that has certain characteristics. The properties of ch3oh, c2h5oh, and c3h7oh are similar and follow a.
The table shows some information about three members of a homologous series. Jan 10, 20 the characteristics of a homologous series is the study of the compounds of carbon in organic chemistry. Organic chemistry topics for ib and college chemistry. Characteristics of homologous series in chemistry spm, students were introduced with five homologous series. Homologous series is a series of compounds with similar chemical. Functional group all the members of homologous series contain same functional group. Choose from 352 different sets of homologous series flashcards on quizlet. Categorisation relies on similarities between and within structures, giving rise to the concept of homologous series. 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 alkanes, alkenes and cycloalkanes are examples of homologous series. 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. Physical properties change regularly with increasing number of carbon atoms. Homologous series, any of numerous groups of chemical compounds in each of which the difference between successive members is a simple structural unit. All the members of a series can be represented by the same general formula.
Difference in molecular mass of two consecutive members of the series is 14 unit i. In general, organic compounds are covalent and insoluble in water. The members of a homologous series can be represented by same general formula. Each homologous series must have the following four characteristics. Describe the general characteristics of an homologous series. State any four characteristics of a homologous series.
All the members of series have same type of elements. Properties of homologous series definition, examples, diagrams. General formula members of a homologous series can be represented by a general formula. Other than sharing the same general formula, what are 2 other features of members of the same homologous series. Significance and properties of the homologous series. For example, you could look at boiling points of h2o, h2s, and h2se and then explain the difference with a discussion of.
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. Significance and properties of the homologous series gulpmatrix. 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. This video is created by more videos and free notes are available at. Which hydrocarbon is a member of the series with the general formula cnh2n2. Natures chemistry homologous series national 5 chemistry. The functional group of aldehyde is aldehydic group i. The name of the characteristics of a homologous depends on the functional group of the series. All the members of a homologous series can be represented by a common general formula, as they have the same functional group.
Homologous series of alkanes, alkenes and alkynes with examples. Each member differs from successive member by ch 2. Homologous series are referenced frequently in organic chemistry, where compounds can differ by the length of their carbon chain. Functional groups and homologous series sneak peek. Features include a general formula and neighbouring members differing by ch2, with similar chemical properties and with a gradation in physical properties. 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. Some examples of homologous series are shown in the following table. What are the characteristics of homologous series answers. The number of carbons continuously bonded together is an important structural feature and is described using the homologous series. After these the names are formed by adding the ending ane to the greek word for the number of carbon atoms in the molecule. Hybridization of atomic orbitals, sigma and pi bonds, sp sp2 sp3, organic chemistry, bonding. Homologous series meaning in the cambridge english dictionary. Homologous series homologous series characteristics.
General characteristics of members of homologous series definition members of the series can be represented by a general formula. 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 few carbon compounds also exhibit a similar pattern. Successive members differ from each other by c h 2. Members have similar chemical properties because they have same functional group. In the field of organic chemistry, a homologous series is a sequence of compounds with the same functional group and similar chemical properties in which the members of the series can. Jan 10, 2018 characteristics of a homologous series. Every member in the homologous series can be represented by a common formula. For example, you could look at boiling points of h2o, h2s, and h2se and then explain the difference with a discussion of intermolecular forces. The alcohols which only contain one hydroxyl group attached to a saturated carbon form a homologous series. Oct 20, 2015 organic chemistry topics for ib and college chemistry. Cycloalkanes homologous series national 5 chemistry.
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