Alkanes consist only of Hydrogen and Carbon atoms and all bonds are single bonds Alkane can be either gaseous, liquid ( methane, ethane, propane and butane at room tempurature) or solid There is more than one way to represent a hydrocarbon formula, depending on how compact on wants to write the formula The larger cycloalkanes, with more than 20 carbon atoms are typically called cycloparaffins. A compound consisting of only two elements, hydrocarbons, is called a hydrocarbon, or simply a hydrocarbon. Chain hydrocarbons can be divided into saturated hydrocarbons and unsaturated hydrocarbons. They are called saturated hydrocarbons because there is a hydrogen in every possible location. A series of linked carbon atoms is known as the carbon skeleton o… The members of such a series, called homologs, have properties that vary in a regular and predictable manner. METHANE. As these bonds are all single bonds, there is free rotation around all connections. ALKANE: Hydrocarbons having only single bonds are known as alkane. Cycloalkanes are named analogously to their normal alkane counterparts of the same carbon count: cyclopropane, cyclobutane, cyclopentane, cyclohexane, etc. (b) Classify the following compounds as alkanes, alkenes and alkynes: C 2 H 4 , C 3 H 4 , … If C = 1, then; C n H 2n+2 = C 1 H 2x1+2 = CH 4. Methane (CH4), ethane (C2H6), and propane (C3H8) are the beginning of a series of compounds in which any two members in a sequence differ by one carbon atom and two hydrogen atoms—namely, a CH2 unit. An ordinary solid line indicates a bond in the plane of the page. Saturated, in this case, means that each carbon atom is bonded to four other atoms (hydrogen or carbon)—the most possible; there are no double or triple bonds in the molecules. In an alkane, all 4 4 4 valencies of the carbon atom are satisfied with other hydrogen atoms. For example, an alkane with eight carbon atoms has the … Due to the general structure of alkenes, they always have twice as many hydrogens as carbons. The general formula for the alkenes is C n H 2n, where n is the number of carbon atoms in the molecule. We begin our study of organic chemistry with the hydrocarbons, the simplest organic compounds, which are composed of carbon and hydrogen atoms only. Alkynes = C n H 2n-2 Longer-chain alkenes generally have single and double bonds between the chains of carbon atoms and have single bonds between hydrogen and carbon atoms. These are organic molecules that consist only of hydrogen and carbon atoms in a tree-shaped structure (acyclic or not a ring). Methane has a tetrahedral shape that chemists often portray with wedges indicating bonds coming out toward you and dashed lines indicating bonds that go back away from you. The formula for alkanes is CnH2n+2. Alkanes have the general formula C n H 2n+2 and can be subdivided into the following three groups: the linear straight-chain alkanes, branched alkanes and cycloalkanes. The first 10 members of this series are given in Table \(\PageIndex{1}\). We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. )%2F12%253A_Organic_Chemistry_-_Alkanes_and_Halogenated_Hydrocarbons%2F12.03%253A_Structures_and_Names_of_Alkanes, 12.4: Condensed Structural and Line-Angle Formulas, information contact us at info@libretexts.org, status page at https://status.libretexts.org. First member is Methane (CH 4) Also known as “Marsh gas”, chief constituent of natural gas (~97%) Hybridisation sp 3. How to Find and Use Coupon Codes for Online Shopping. Methane gas is the first member of the homologous series of alkanes. d) Draw the structure of the cycloalkane in c) above and give its systematic name Decene is an alkene. Hydrocarbons which contain only single bonds are called alkanes. Alkanes: General Formula: One of the most common classes of compounds in organic chemistry is alkanes. Short-chain alkenes with only two carbons generally are connected via double bonds between the carbon atoms and single bonds between the carbon and hydrogen atoms. This group of compounds comprises a homologous series with a general molecular formula of C n H 2 n+2 , where equals any integer. Here is a list of the first 10 alkanes. The sequence starts with C3H8, and a CH2 unit is added in each step moving up the series. In other words, a cycloalkane consists only of hydrogen and carbon atoms arranged in a structure containing a single ring, and all of the carbon-carbon bonds are single. Consider the series in Figure \(\PageIndex{3}\). Their adjacent atoms are connected with sigma bonds and form tetrahedral centers around the carbon atoms. Identify the simplest alkane. For example, an alkane with 2 (n) carbon atoms, will have 6 (2n + 2) hydrogen atoms. ALKANES. Acyclic alkanes can be described by the general formula C n H 2n +2. [ "article:topic", "saturated", "showtoc:no", "license:ccbyncsa", "homology", "program:hidden" ], https://chem.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fchem.libretexts.org%2FBookshelves%2FIntroductory_Chemistry%2FBook%253A_The_Basics_of_GOB_Chemistry_(Ball_et_al. Alkanes have a single carbon-carbon bond and form an homologous series whose first members are methane, ethane, propane and butane. Let's Get Celestial: Start Using Sky Maps Tonight for Stargazing. Alkenes have a general formula of CnH2n, where "n" may equal any number larger than one. Each carbon atom is bonded to four other atoms (carbon or hydrogen atoms) by single covalent bonds. The generic formula for alkanes is CnH2n+2, where n is the number identified by the prefix. \ce{C_{n}H}_{2n+2}. The word saturated has the same meaning for hydrocarbons as it does for the dietary fats and oils: the molecule has no carbon-to-carbon double bonds (C=C). Alkanes are saturated hydrocarbon consist of carbon and hydrogen only without any functional group. The LibreTexts libraries are Powered by MindTouch® and are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. This gives them a general formula : C X n H 2 n + 2. Alkane. alkane [ ăl ′kān′ ] Any of a group of hydrocarbons that have carbon atoms in chains linked by single bonds and that have the general formula CnH2n+2. This gives them a general formula C n H 2n+2.. The general formula for the alkanes is CnH2n+2 (where n is the number of carbon atoms in the molecule). Have questions or comments? How many hydrogen atoms are in the molecule? Alkenes may have single or double bonds. These are saturated hydrocarbons. The Alkane family. Organic compounds having only two elements, carbon and hydrogen are called hydrocarbons. Alkenes are organic compounds that are generally only comprised of hydrogen and carbon atoms. Using this formula, we can write a molecular formula for any alkane with a given number of carbon atoms. Alkane are also known as paraffin. Its molecules contain 10 carbon atoms . If you count the carbons and hydrogens, you will see that they no longer fit the general formula C n H 2n+2. Click here to let us know! a) It is otherwise known as Paraffin b) It is an acyclic saturated hydrocarbon c) In alkanes, C-C bonds are single d) Alkanes have the general formula CnH2n 24. They are divided into two main classes, aliphatic and aromatic. For example, an alkane with 2(n) carbon atoms, will have 6 (2n+2) hydrogen atoms. The principle of homology allows us to write a general formula for alkanes: C n H 2n + 2. How Does a Presidential Executive Order Work? (a) Give the general formula of an: (i) alkane, (ii) alkene and (iii) alkyne. The alkanes are a family of simple hydrocarbons with general formula CnH2n+2, where n= 1, 2, 3, … Alkanes are saturated hydrocarbons. Alkanes have the general formula CnH2n+2. Alkenes are hydrocarbons that contain carbon carbon double bond (C=C The general formula of alkane is CnH2n+2. Alkanes have the general formula C n H 2n+2. We previously introduced the three simplest alkanes—methane (CH4), ethane (C2H6), and propane (C3H8) and they are shown again in Figure \(\PageIndex{1}\). b) What is the general formula of a cycloalkane? Each carbon atom has four bonds (either C-H or C-C bonds), and each hydrogen atom is joined to a carbon atom (H-C bonds). An alkyl group is formed by removing one hydrogen from the alkane chain and is described by the formula C n H 2n +1. General formula: C n H 2n+2 . They comprise only hydrogen and carbon. Alkenes are organic compounds that are generally only comprised of hydrogen and carbon atoms. Using this formula, we can write a molecular formula for any alkane with a given number of carbon atoms. The general formula of alkane is C n H 2n+2. For example, an alkane with eight carbon atoms has the molecular formula C8H(2 × 8) + 2 = C8H18. According to the different molecular structure of hydrocarbons, hydrocarbons can be divided into two types: Chain hydrocarbons ( aliphatic hydrocarbons ) and Cyclic hydrocarbons( alicyclic hydrocarbons ). Take a look at the following examples. The list of some Alkanes and the molecular formula is given below.Methane (CH4), Ethane (C2H6), Propane (C3H8), Butane (C4H10), Pentane (C5H12), Hexane (C6H14), Heptane (C7H16), Octane (C8H18), Nonane (C9H20), Decane (C10H22). The simplest alkane, methane, has one carbon atom and a molecular formula of CH 4. Legal. The flat representations shown do not accurately portray bond angles or molecular geometry. What is the general formula of the alkanes? Alkanes are used as fuels. c) A cycloalkane molecule contains 8 carbon atoms. Because alkanes are saturated compounds they are relatively unreactive. Any family of compounds in which adjacent members differ from each other by a definite factor (here a CH2 group) is called a homologous series. Did the Groundhog See Their Shadow — and Why Do We Care? Most of the … Alkenes have the formula CnH2n and alkynes use the formula CnH2n-2. means they only have carbon and hydrogen atoms in their chemical formula Don't Miss These 7 Must-See Stargazing and Celestial Events in 2021. Similarly, why is the general formula for an alkane CnH2n 2? Alkenes have a general formula of CnH2n, where "n" may equal any number larger than one. Alkanes. Name of this compound is methane. Adopted a LibreTexts for your class? C X n H 2 n + 2 . The alkanes are also called as paraffins. The removal of this hydrogen results in a stem change from -ane to -yl. They can be categorized into three groups which are: chain alkanes, cycloalkanes, and branched alkanes. In organic chemistry, the cycloalkanes are the monocyclic saturated hydrocarbons. Alkanes have the general formula \(C_nH_{2n+2}\) and can be subdivided into the following three groups: the linear straight-chain alkanes, branched alkanes, and cycloalkanes. ANSWER:-Write the general formula for alkanes, alkenes and alkynes are as : Alkanes = C n H 2n+2. These are commonly known as paraffins and waxes. For more information contact us at info@libretexts.org or check out our status page at https://status.libretexts.org. You are unlikely to ever need it, but the general formula for a cycloalkane is … Due to the general structure of alkenes, they always have twice as many hydrogens as carbons. Alkenes = C n H 2n. Recall that the VSEPR theory correctly predicts a tetrahedral shape for the methane molecule (Figure \(\PageIndex{2}\)). Simple alkanes exist as a homologous series, in which adjacent members differ by a CH. Unless otherwise noted, LibreTexts content is licensed by CC BY-NC-SA 3.0. Example: methane (CH4), ethane (C2H6), propane (C3H8) etc. To identify and name simple (straight-chain) alkanes given formulas and write formulas for straight-chain alkanes given their names. As we noted, there are several different kinds of hydrocarbons. Alkenes may have single or double bonds. Hydrogen atoms always have only single bonds because they only have one electron to share, and double bonds require two electrons. Hydrocarbons with only carbon-to-carbon single bonds (C–C) and existing as a continuous chain of carbon atoms also bonded to hydrogen atoms are called alkanes (or saturated hydrocarbons). The principle of homology allows us to write a general formula for alkanes: CnH2n + 2. Is a Revocable Trust Right for Protecting Your Assets? 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