Naming, molecular formula, structural formula, condensed formula, and carbon skeletal formula. Alkanes belong to the family of saturated hydrocarbons that is. Propyl butyl and pentyl branched substituents organic. Alkanes that have carbons that are bonded to more than 2 carbons these are skeletal isomers example butane. These common names make use of prefixes, such as iso, sec, tert, and neo. The prefix iso, which stands for isomer, is commonly given to 2methyl alkanes. Learn the iupac system for naming alkanes and cycloalkanes. Finally, you order the substituents alphabetically in front of the parent chain to construct the name of the branched. Iupac naming conventions can be used to produce a systematic name. This is lesson 5 of a 7 lesson unit on hydrocarbons. Ch 3 ch ch ch 2 ch 2 ch 2 ch 2 ch 3 ch 3 ch 3 7 carbons heptb. A branched chain alkane is an organic molecule that has smaller carbon chains sticking out in the middle rather. The names 3methylhexane and 4ethyl3methyloctane for the alkanes shown here are based on these rules.
The following rules illustrate the basic principles for naming simple branched alkanes. Choose from 500 different sets of naming alkanes flashcards on quizlet. Naming when naming alkanes, commas are used between numbers, and dashes are used between letters and numbers. Number of carbons name structure 5 pentane ch 3 ch 2 3 ch 3 6 hexane ch 3 ch 2 4 ch 3 7 heptane ch 3 ch 2. No answers have been given on the worksheet, please see the link provided. If two chains have the same number of carbons, choose the chain with the most substituents. If there are substituents that are the same number of. Neopentyl is the only one to memorize for branched 5carbon substituents.
Naming branched alkanes and alkenes and alkynes youtube. Branching can happen in many different ways and means that a variety of possible structures can exist for one molecular formula. Lowest number goes to highest priority alphabetically. Note that the double bond takes precedence in naming. Video 3 this tutorial video takes you through the steps of naming branched chain alkanes using the iupac naming rules. This lesson focuses on naming branched and difficult structures of alkanes and alkenes. When it comes to halogens, you have to change the ending ine to o. Ch 3chchchch3 ch3 this compound is named 4methyl2pentene.
Although a cycloalkane has two fewer hydrogens than the equivalent alkane, each carbon is bonded to four other atoms so such compounds are still considered to. The key steps in the naming of more complicated branched alkanes are as follows. Much of this fraction is utilized as jet engine fuels or is cracked to. In other words, if there is methyl group located on the second carbon of a carbon chain, we can use the prefix iso. Number the carbons in the chain starting with the end thats closest to a branch. Simply put, aliphatic compounds are compounds that do not incorporate any. Tricky chemistry teachers often draw branched alkanes with the longest chain snaking through a few. A branched chain alkane is an organic molecule that has smaller carbon chains sticking out in the middle rather than having all carbons connected in a single row.
Draw the structures of branched and unbranched alkanes, c1 to c4 and name the unbranched alkanes c1 to c4. Methane through butane are very flammable gases at standard temperature and pressure stp. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carboncarbon bonds are single. The following steps are taken in naming an alkane with a branched chain. Learn naming alkanes with free interactive flashcards.
Nomenclature is a system of rules by which the names of compounds are formed. Find the longest continuous carbon chain and select the. Secbutyl, isobutyl, and tertbutyl for branched 4carbon substituents. For example, a one carbon branch is called a methyl group. If more than one different chains are of equal length number of carbons, choose the one with the greater number of branch points. The alkanes and cycloalkanes are also members of a larger class of compounds referred to as.
The simple branched alkanes have prefixes on their names to distinguish them from the linear alkanes. An alkyl group has one hydrogen removed from an alkane, and the names have a su x of yl rules for naming branched chain alkanes. Finish the straight chain alkane practice at the end of the notes. The prefix tells us the identity, location, and number of substituents attached to. If the compound is branched, the name is determined similar to that used for the alkanes. Fortunately, common numerical prefixes are used in naming chains of five or more carbon atoms. Naming aromatic compounds aromatic compounds are cyclic hydrocarbons containing a benzene structure. Mar 07, 20 national 5 chemistry naming branched chain alkanes duration. The international union of pure and applied chemistry iupac is developing the rules for naming compounds. Identify the parent chain of the hydrocarbon a identify the longest continuous carbon chain parent chain in the molecule and use the name of. Luckily, you can simplify the common branched substituents by memorizing the following shortcuts. Alkanes 2 organic chemistry nowadays almost drives me mad. Naming branched alkenes 4,6dimethyl1heptene 1chloro5ethyl2fluoro6methyl1octene in the above examples, giving the smallest number to the cc takes priority over giving a. The names of alkyl groups are the same as those of analogous alkanes.
Naming organic compounds branched chain alkanes youtube. Consult your textbook for more details and examples. Branched chain alkanes do not exhibit the same smooth gradation of physical properties as do the continuouschain alkanes. If more than one different chains are of equal length number of carbons, choose the one with the greater number of branch points substituents as the parent. Nomenclature of alkanes rules of naming branched alkanes 6 very often you will be dealing with branched rather than straight chain alkanes. We place the name of each alkyl group, with the number of the c in the parent alkane to which it is bonded, in alphabetical order in front of the name of the parent alkane. Naming alkanes, cycloalkanes, and bicyclic compounds. This longest chain may not be written in a straight line. Naming alkanes with branched substituents iupac nomenclature duration. When naming branched alkanes by iupac rules, identify and name the longest continuous carbon chain first. The names methane through decane should be memorized, since they constitute the root of many iupac names.
Describe a homologous series and its general characteristics. Iupac naming branchedchain alkanes chemistry tutorial key concepts. The first four members of the series in terms of number of carbon atoms are named as follows. Name that longest chain with the appropriate alkane name. An alkyl group has one hydrogen removed from an alkane, and the names have a su x of yl rules for naming branchedchain alkanes. Since alkanes are the most fundamental types of organic compounds, their structural features a basic carbon chain, or skeleton.
Alkanes you must know how to name and draw straight chain and branched alkanes. Indicate the number of carbon atoms in the chain with a prefix followed by the ending ane. Provided the academic center for excellenceby 2 naming organic compounds june 2016 lastly, if the compound is in a ring, use the prefix cyclo. The organic compounds form a series, known as homologues series in which the successive compounds contain the same. Alkanes are also known as paraffins, or collectively as the paraffin series.
Iupac naming branchedchain alkanes chemistry tutorial. Sep 06, 2016 naming branched substituents can get confusing really fast. This final step leads to the complete names of these branched alkanes as shown here. In the above set of molecules, only the first one is a straight chain of carbon atoms. You must then locate and identify all the substituents that stick off of the parent chain, including multiple and complex branches. Beginning with the fivecarbon alkane, the number of carbons in the chain is. Write the name of each of the hydrocarbon molecules shown below. Naming branched chain alkanes organic chemistry tutorial.
Alkanes are the simplest organic molecules, consisting solely of singlybonded carbon and hydrogen atoms. The parent name indicates the number of carbons in the longest continuous chain. Hydrocarbon naming schemes must be able to account for structural differences of isomers such as these to learn the name of these five alkanes, refer to the examples section. The prefix tells us the identity, location, and number of substituents attached to the carbon chain. Naming branched alkenes 4,6dimethyl1heptene 1chloro5ethyl2fluoro6methyl1octene in the above examples, giving the smallest number to the cc takes priority over giving a small number to the methyl branch. Simple branched alkanes often have a common name using a prefix to distinguish them from linear alkanes, for example npentane, isopentane, and neopentane. Naming branched substituents can get confusing really fast. To me it appears like a primeval tropical forest full of the most remarkable things, a dreadful endless jungle into. Learn the important physical and chemical properties of the alkanes.
Naming branched chain alkanes organic chemistry tutorial video. The alkanes range in complexity from the simplest case of methane. For example, isopentane, neopentane, and npentane are names of branched forms of the alkane pentane. Branched alkanes occur when a straight chain alkane forms replaces one of its hydrogen atoms with an alkyl group an alkane which has similarly lost a hydrogen on the end carbon, forming a branch. Longer chain alkanes are well known, and their names may be found in many reference and text books. Feb, 20 naming alkanes with branched substituents iupac nomenclature duration. Naming alkanes with alkyl groups video khan academy. Learn how to recognize the alkane functional group in organic compounds. Iupac naming branched chain alkanes chemistry tutorial key concepts. Alkanes are used as the basis for naming the majority of organic compounds their nomenclature. If the substituent is a simple, unbranched chain, that just happens to be attached at a nonterminal carbon, then we number the chain from the end closest to the point of attachment and then use the attachment point as a prefix for that. What do we do if the substituent is an alkyl chain, but its not connected to the parent at its own terminus.
How to identify multiple or complex substituents in a. The same concept can be applied to any of the straight chain alkane names. These terms are also used for alkanes whose carbon atoms form a single, unbranched chain. The remaining four have branches from the main chain. The names of alkanes and cycloalkanes are the root names of organic compounds. Alkanes with unbranched carbon chains are simply named by the number of carbons in the chain.
Nomenclature of alkanes, alkenes and alkynes iupac. The powerpoint includes theory and activities to be completed throughout the lesson. National 5 chemistry naming branched chain alkanes duration. Identify the longest continuous carbon chain as the parent chain. If there are substituents that are the same number. Certain branched alkanes have common names that are still widely used today.
Number the carbons in the chain starting from the end nearest the first substituent. When naming a branched alkane, you first need to locate and number the parent longest chain. Step 1 find the longest continuous carbon chain and use the iupac name of the unbranched alkane as the basis. Practice naming acyclic and cyclic alkanes using iupac rules. Although their reactivities are often rather uninteresting, they provide an excellent basis for understanding bonding, conformation, and other. The branched alkanes make better gasoline than their con tinuouschain isomers because they give less knock in highcompression gasoline engines.
The suffix indicates what functional group is present. If you have fluorine coming off of the carbon chain, it is named as fluoro. Short summary of iupac nomenclature of organic compounds. How does one go about naming such branched alkanes.
In organic chemistry, an alkane, or paraffin a historical name that also has other meanings, is an acyclic saturated hydrocarbon. Nomenclature ninja naming alkanes organic chemistry. Organic chemistryalkanes wikibooks, open books for an open. A halogen is also treated as a substituent when it comes to naming alkanes. The longest continuous chain of c atoms in the branched alkane is the. Rules for naming alkanes find the longest chain of carbon atoms. I couldnt find another worksheet, but the workbook covers these topics. To take a simple example, lets look at the branched isomer of butane. Organic chemistryalkanes wikibooks, open books for an. Janice gorzynski smith university of hawaii chapter 4 alkanes.
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