Organic Compounds. The formula of a molecular compound, especially organic compounds, can be written in several different ways

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1 Organic ompounds It s all about the arbon!!! Organic ompounds Molecular compounds can be put into two groups Inorganic compounds: ompounds that do not contain carbon or carbon and hydrogen Examples: SO2 sulfur dioxide or N3 ammonia Organic compounds: ompounds that contain carbon, usually contain hydrogen, and may also contain oxygen, nitrogen, sulfur, phosphorus, or halogens Examples: 26O ethanol or 4 methane Organic compounds are of great interest because they are the basis for the clothes we wear, the food we eat, the fuels we burn, and living organisms in our environment Organic ompounds The formula of a molecular compound, especially organic compounds, can be written in several different ways 1) Molecular Formula: For an organic compound, the symbols of the elements other than carbon are frequently written in alphabetical order 26O Because of the huge number of organic compounds, this formula may not give sufficient information to indicate what compound is represented; such identification requires more information about how the atoms are connected to each other

2 Organic ompounds 2) Structural formula The structural formula shows exactly how atoms are connected O Organic ompounds 3) ondensed formula The formula can also be written in a modified form to show how the atoms are grouped together in the molecule 32O Organic ompounds What is the molecular formula of the following compounds? O O O O O O

3 Organic ompounds Write the molecular formula for these compounds Adenosine triphosphate (ATP), an energy source in biochemical reactions, which has 10 carbon, 11 hydrogen, 13 oxygen, 5 nitrogen, and 3 phosphorus atoms per molecule apsaicin, the active ingredient in chili peppers, which has 18 carbon, 27 hydrogen, 3 oxgyen, and 1 nitrogen atoms per molecule Oxalic acid has the condensed formula OOOO and is found in rhubarb ydrocarbons ydrocarbons are organic compounds composed of only carbon and hydrogen atoms; they are the simplest class of organic compounds The simplest major class of hydrocarbons is the alkanes, which economically important fuels and lubricants The simplest alkane is methane, 4, which has a central carbon atom with four bonds joining it to four atoms omologous Series A homologous series is one in which adjacent members differ by a constant unit It is not necessary to remember the molecular formulas for all members of a homologous series Instead, a general molecular formula can be used to determine the formulas

4 Alkanes The general formula for alkanes is n2n+2, where n is an integer IUPA Who decides the rules when it comes to naming molecules? IUPA: International Union of Pure and Applied hemistry IUPA: The International Union of Pure and Applied hemistry (IUPA) serves to advance the worldwide aspects of the chemical sciences and to contribute to the application of chemistry in the service of Mankind. As a scientific, international, non-governmental and objective body, IUPA can address many global issues involving the chemical sciences. IUPA was formed in 1919 by chemists from industry and academia. Over nearly eight decades, the Union has succeeded in fostering worldwide communications in the chemical sciences and in uniting academic, industrial and public sector chemistry in a common language. IUPA has long been recognized as the world authority on chemical nomenclature, terminology, standardized methods for measurement, atomic weights and many other critically evaluated data. Alkanes Methane, the simplest alkane, makes up about 85% of natural gas; it is also known to be one of the greenhouse gases Ethane, propane, and butane are used as heating fuel for homes and in industry Using the general formula n2n+2, write the molecular formulas for alkanes containing 16 and 28 carbons ow many hydrogen atoms are present in tetradecane, which has 14 carbon atoms?

5 Alkanes Two or more compounds that have the same molecular formula but different arrangements of atoms are called isomers The first three alkanes - methane, ethane, and propane - have only one possible structural arrangement When we come to the alkane with four carbon atoms 410, there are two possible arrangements - a straight chain of four carbons (butane) or a branched chain of three carbons with the fourth carbon attached to the central atom of the chain of three ( propane) Alkanes Butane and propane are isomers but they are different compounds with different properties Alkanes What are the isomers of alkanes with 5 carbons and 6 carbons? Draw their structure.

6 Alkyl Groups An alkyl group is the fragment of the molecule that remains when a hydrogen atom is removed from an alkane group Alkyl groups are named by dropping -ane from the parent alkane name and adding -ly ethyl group propyl group Alkyl Groups What alkyl groups are present in this branched alkane? Naming Alkanes To name an unbranched alkane, find the prefix that corresponds to the number of carbon atoms in the chain of the hydrocarbon Then add the suffix -ane to the prefix What s the name of this unbranched alkane?

7 Naming Alkanes What is the name of this unbranched alkane? Naming Alkanes To name branched alkanes, the first step is to locate the parent carbon chain orrect Wrong The parent carbon chain is the longest continuous chain that contains the most straight-chain branches!!! orrect Wrong

8 Naming Alkanes To name the parent carbon chain, add the suffix -ane to the prefix 3 3 ethyl octane Now identify and name the alkyl groups To show that there are three groups present, attach the prefix tri- Arrange the alkyl group names in alphabetical order 3 3 ethyl ethyl trioctane Now we need to show the locations of the alkyl groups on the parent carbon chain Number the octane chain so that the alkyl groups have the lowest numbers possible 3 3 ethyl ethyl-2,4,5-trioctane 2 3 3

9 Naming Alkanes Name the following simple branched-chain alkane Naming Alkanes Draw the condensed structural formula of 3-ethyl-4-hexane