VII. Organic

Organic compounds contain carbon atoms which bond to one another in chains, rings, and networks to form a variety of structures. Organic compounds can be named using the IUPAC system. (3.1ff) J Deutsch 2003

Hydrocarbons are compounds that contain only carbon and hydrogen Hydrocarbons are compounds that contain only carbon and hydrogen. Saturated hydrocarbons contain only single carbon-carbon bonds. Unsaturated hydrocarbons contain at least one multiple carbon-carbon bond. (3.1gg) J Deutsch 2003

Homologous series of hydrocarbons: Saturated hydrocarbons Alkanes Only single bonds between carbons Name ends in ___ane General formula CnH2n+2 Methane CH4 Ethane C2H6 Unsaturated hydrocarbons Contain at least one double or triple bond Alkenes Contain one double bond Name ends in ___ene General formula CnH2n Alkynes Contain one triple bond Name ends in ___yne General formula CnH2n-2 J Deutsch 2003

Table Q gives the general formula and examples (name and structure) of the homologous series of hydrocarbons. J Deutsch 2003

Regents Question: 06/03 #24 Which element has atoms that can form single, double, and triple covalent bonds with other atoms of the same element? hydrogen (2) oxygen (3) fluorine (4) carbon þ J Deutsch 2003

Table P gives the prefix used to name the first 10 hydrocarbons in an homologous series. J Deutsch 2003

The prefix of the name tells you how many carbons in the chain The prefix of the name tells you how many carbons in the chain.The suffix tells you the type of hydrocarbon. Number of Carbons Prefix Example Alkane CnH2n+2 Alkene CnH2n Alkyne CnH2n-2 1 Meth Methane CH4 2 Eth Ethane C2H6 Ethene C2H4 Ethyne C2H2 3 Prop Propane C3H8 Propene C3H6 Propyne C3H4 4 But Butane C4H10 Butene C4H8 Butyne C4H6 5 Pent Pentane C5H12 Pentene C5H10 Pentyne C5H8 J Deutsch 2003

Alkanes are saturated hydrocarbons. Regents Question: 06/03 #21 Which hydrocarbon is saturated? (1) propene (2) ethyne (3) butene (4) heptane þ Alkanes are saturated hydrocarbons. J Deutsch 2003

A structural formula show the way the atoms are arranged. Methane Ethane H H H H C H H C C H Each line represents a covalent bond - a shared pair of electrons. J Deutsch 2003

A structural formulas show the way the atoms are arranged. propene H H H C C C H H H ethyne H C C H The double bonds makes this hydrocarbon an alkene The triple bonds makes this hydrocarbon an alkyne J Deutsch 2003

Regents Question: 01/03 #13 The empirical formula of a compound is CH2 Which molecular formula is correctly paired with a structural formula for this compound? þ J Deutsch 2003

Chains of carbons can be branched A carbon group connected to a chain is called an alkyl group. To name the alkyl group, use the prefix for the number of carbons and add yl. -CH3 H H C Methyl -C2H5 H H H C C Ethyl J Deutsch 2003

Carbon always has 4 bonds. Hydrogen always has 1 bond Oxygen always has 2 bonds Nitrogen always has 3 bonds C or C or C H O or O N J Deutsch 2003

Carbon always has four bonds. Regents Question: 08/02 #42 Which structural formula is incorrect? Carbon always has four bonds. þ J Deutsch 2003

Naming hydrocarbons with alkyl groups: Find the longest continuous chain of carbons. This is the backbone. Find the name of the backbone. Find the name of the alkyl group (or groups) attached to the backbone. Name the alkyl group and then the name of the backbone. Use a number to indicate which carbon the alkyl group is attached to if necessary. J Deutsch 2003

Find the name of this hydrocarbon. H C H H H H H H H C C C C C C H H H H H H H Find the alkyl group Find the longest chain 1 6 2 5 3 4 4 3 5 2 6 1 3- methyl hexane Counting from each direction find the carbon where the alkyl group is attached (the lower number) J Deutsch 2003

The longest chain does not have to be drawn straight. H C H H H H H H C C C C C H H H H H H H H C H H H H H H C C C C C H H H H H H 3-methylhexane J Deutsch 2003

Chains of carbons can form rings Use a prefix cyclo when a ring is formed To make a ring, two Hydrogen atoms are removed Cyclopentane is a 5 carbon ring with all single bonds. J Deutsch 2003

Organic acids, alcohols, esters, aldehydes, ketones, ethers, halides, amines, amides, and amino acids are categories of organic molecules that differ in their structures. Functional groups impart distinctive physical and chemical properties to organic compounds. (3.1hh) J Deutsch 2003

Reference Table R lists all the functional groups. J Deutsch 2003

Reference Table R Cont’d. J Deutsch 2003

Regents Question: 06/03 #44 Given the formulas of four organic compounds: Which pair below contains an alcohol and an acid? (1) a and b (3) b and d (2) a and c (4) c and d þ J Deutsch 2003

Naming Halocarbons (-X) Halocarbons (or halides) have a halogen (F, Cl, Br, I) in place of a hydrogen Name the halogen first (fluoro, chloro, bromo, iodo) then name the alkane If there are more than 2 carbons in the chain, use a number to indicate which carbon the –X group is attached to. (Number from the direction that gives the smallest number) 1-chloropropane 2-bromobutane H H Cl H C C C H H H H H Br H H H C C C C H H H H H J Deutsch 2003

Naming Alcohols (-OH) Alcohols have the hydroxyl group -OH The prefix is the number of carbons in the longest chain Name the alkane and drop the letter e The suffix is ol If there are more than 2 carbons in the chain, use a number to indicate which carbon the –OH group is attached to. (Number from the direction that gives the smallest number) 1-propanol 2-propanol H H OH H C C C H H H H H OH H H C C C H H H H J Deutsch 2003

Regents Question: 08/02 #20 þ Which compound is an alcohol? propanal (2) ethyne (3) butane (4) methanol þ J Deutsch 2003

Naming Ethers (-O-) Ethers have an Oxygen in the chain of carbons Name the alkyl groups on either side of the O that is in the chain If both alkyl groups are the same it is named once with the prefix DI in front of it. H H H H C C O C H Methyl ethyl ether H H H C O C H Dimethyl ether J Deutsch 2003

Naming Aldehydes (-CHO) Aldehydes have a double bonded Oxygen on the last carbon in the chain. Name the alkane, drop the e and add __al propanal methanal H H O H C C C H H H O H C H J Deutsch 2003

Naming Ketones (-CO-) Ketones have a double bonded Oxygen on a carbon in the middle of the chain. (Not the last carbon) Name the alkane, drop the e and add __one If there are more than 4 carbons in the chain, use a number to indicate the location of the =O butanone 3-pentanone H H O H H C C C C H H H H H H O H H H C C C C C H H H H H J Deutsch 2003

Naming Organic Acids (-COOH) Acids have a double bonded Oxygen and an –OH on the last carbon in the chain. Name the acid, drop the e and add __oic acid This is OH and not HO…the Carbon is bonded to the O Propanoic acid Pentanoic acid H H O H C C C OH H H O H H H H HO C C C C C H H H H H J Deutsch 2003

Naming Amines (-NH2) Amines have a nitrogen bonded to the carbon chain. The nitrogen may have two, one or no hydrogen atoms bonded to it. Name the alkane, drop the e and add __amine If there are more than two carbon atoms, use a number to indicate which carbon the N is attached to. ethanamine 2-Pentanamine H H H C C NH2 H NH2 H H H H C C C C C H H H H H H J Deutsch 2003

Name the folowing: Ethanoic acid 1-Propanamine Ethanal 2-butene H H H H H C C C N H H H H H O H C C OH H Ethanoic acid 1-Propanamine H O H C C H H H H H H H C C C C H H H Ethanal 2-butene H H O H H H H C C C C C C H H H H H H H OH H H H H C C C C C H H H H H H 3-hexanone 2-pentanol J Deutsch 2003

Regents Question: 06/02 #17 Which compound is classified as a hydrocarbon? Ethane (2) Ethanol (3) chloroethane (4) ethanoic acid þ J Deutsch 2003

Regents Question: 06/02 #48 þ Which pair of compounds are alcohols? J Deutsch 2003

Regents Question: 01/03 #49 Which type of organic compound is represented by the structural formula shown below? (1) aldehyde (2) alcohol (3) ether (4) ester þ J Deutsch 2003

Isomers of organic compounds have the same molecular formula but different structures and properties. (3.1ii) Pentane C5H12 Methylbutane C5H12 H H H H H C C C C H H H H H C H H H H H H H H C C C C C H J Deutsch 2003

Examples of isomers: 1-butanol (C4H9OH) diethyl ether (C2H5OC2H5) 4 Carbon, 10 Hydrogen, 1 Oxygen propanal (C2H5CHO) 2-propanone (CH3COCH3) 3 Carbon, 6 Hydrogen, 1 Oxygen Isomers have the same chemical formulas but different structural formulas. J Deutsch 2003

Regents Question: 06/03 #25 þ Which compound is an isomer of pentane? (1) butane (2) propane (3) methyl butane (4) methyl propane þ J Deutsch 2003

Regents Question: 06/02 #19 þ Which formula is an isomer of butane? J Deutsch 2003

Regents Question: 08/02 #55 Given the structural formula for butane: Draw the structural formula for an isomer of butane. H H H H C C C H H H H C H H J Deutsch 2003

Regents Question: 01/03 #18 þ Which compound has an isomer? J Deutsch 2003

In a multiple covalent bond, more than one pair of electrons are shared between two atoms. Alkenes have one double bond H H C C Alkynes have one triple bond H C C H Ethene C2H4 Ethyne C2H2 J Deutsch 2003

Alkenes and Alkynes are unsaturated. Unsaturated organic compounds contain at least one double or triple bond. (5.2e) Alkenes and Alkynes are unsaturated. By breaking the multiple bond in alkenes and alkynes, more hydrogen atoms can be added Alkanes are saturated. Alkanes do not have multiple bonds, therefore, they already have as many hydrogen atoms as they could possibly hold. J Deutsch 2003

Regents Question: 01/03 #25 In saturated hydrocarbons, carbon atoms are bonded to each other by (1) single covalent bonds, only (2) double covalent bonds, only (3) alternating single and double covalent bonds (4) alternating double and triple covalent bonds þ J Deutsch 2003

Types of organic reactions include: addition, substitution, polymerization, esterification, fermentation, saponification, and combustion. (3.2c) J Deutsch 2003

Organic Reactions-Addition H2, Cl2, Br2, HCl, HBr is added to an unsaturated hyrdrocarbon. Both atoms are added to where the double (or triple) bond was located. Key to look for – Unsaturated hydrocarbon reactant and one product. H H C C H H C C Cl Cl H C C H H H + Cl2 J Deutsch 2003

Organic Reactions-Addition Cont’d Addition of hydrogen H2 Can be used to saturate and unsaturated hydrocarbon. It uses a catalyst such as platinum (Pt) H H C C H H C C H H H C C H + H2 Pt J Deutsch 2003

Regents Question: 01/03 #26 Which formula correctly represents the product of an addition reaction between ethene and chlorine? CH2Cl2 (2) CH3Cl (3) C2H4Cl2 (4) C2H3Cl þ J Deutsch 2003

Organic Reactions-Substitution A halogen is reacted with a saturated hydrocarbon. One of the halogen atoms substitutes one of the hydrogen atoms. Key to look for – Saturated hydrocarbon reactant and two product. H H H C C H H Cl H C C H H H + Cl2 UV + HCl J Deutsch 2003

Organic Reactions-Polymerization Polymerization – joining many small molecules together to form a large molecule A single unit is called a monomer Many monomers are bonded together to form a polymer Polymers can be natural or artificial Natural Polymers Artificial Polymers Protein Polyester Rubber Nylon Cellulose Styrofoam J Deutsch 2003

Regents Question: 06/02 #49 The process of joining many small molecules into larger molecules is called (1) neutralization (2) polymerization (3) Saponification (4) substitution þ J Deutsch 2003

Regents Question: 06/03 #45 Which type of reaction is represented by the equation below? Note: n and n are very large numbers equal to about 2000. (1) Esterification (3) saponification (2) fermentation (4) polymerization þ J Deutsch 2003

Organic Reactions-Esterification Esterification – making an ester by combining an alcohol with an organic acid H H H C C OH O H HO C C H H + H H H C C O O H C C H H H2O + J Deutsch 2003

Naming Esters (-COOC-) Esters have a double bonded Oxygen and an –O– bonded to another carbon. Name the alkyl group that came from the alcohol. Name the acid but drop __ic acid and replace it with ate. Propanoic acid + pentanol Pentyl propanoate + water Propanoic acid 1-Pentanol H H O H C C C OH H H H H H H H HO C C C C C H J Deutsch 2003

Making an ester by removing water from an acid and an alcohol Propanoic acid 1-Pentanol H H O H C C C O H H H H H H H C C C C C H H HO Pentyl propanoate J Deutsch 2003

Name the ester: Methyl ethanoate H O H H C C O C H H H Ethanoate Acid Alcohol Determine which side was the alcohol and which side was the acid by drawing a line through the oxygen in the chain. The side with the double bonded O was the acid. Alcohol will make you yl if you ate the acid. J Deutsch 2003

Regents Question: 08/02 #56 Given the ester: ethyl butanoate a. Draw the structural formula for this ester. b. Determine the gram formula mass of this ester. C 6 x 12 = 72 O 2 x 16 = 32 H 12 x 1 = 12 116 g H H H O H C C C C O H H H H H C C H Even if you got the structure wrong but you got the correct mass for the structure you drew, you got one point. J Deutsch 2003

Amides (-CON) are made by reacting an organic acid with ammonia or with an amine. From amine (CH3NH2) H O H C C N H H H H O H H C C N C H H H H From ammonia (NH3) J Deutsch 2003

Propanoic acid + 1-pentanamine Pentyl propanamide + water Naming Amides (-CON-) Amides have a double bonded Oxygen and a Nitrogen. Name the alkyl group that came from the amine. Name the acid but drop __oic acid and replace it with amide. Propanoic acid + 1-pentanamine Pentyl propanamide + water Propanoic acid 1-Pentanamine H H O H C C C OH H H H H H H H H2N C C C C C H J Deutsch 2003

Making an amide by removing water from an acid and an amine Propanoic acid 1-Pentanamine H H O H C C C H H H H H H H N C C C C C H H H H H H H OH H Pentyl propanamide J Deutsch 2003

Amino acids have both an amine group and an acid group. An amino acid is a compound that has an amine group on one side and an acid group on the other. O R H HO C C N H H R is the only part that changes in different amino acids. J Deutsch 2003

Proteins are polymers of amino Remove water O R HO C C N H H O R C C N H H H O R HO C C N H H H J Deutsch 2003

Organic Reactions-Fermentation Fermentation – yeast and bacteria can make ethanol and carbon dioxide by breaking down sugar using an enzyme. The alcohol can be used to make beer and wine, The carbon dioxide can be used to make bread rise or make the bubbles in beer and champagne. Enzyme C6H12O6 2C2H5OH + 2CO2 J Deutsch 2003

Organic Reactions-Saponification Saponification is a reaction in which a lipid (fat or oil) is used to make soap. J Deutsch 2003

Organic Reactions-Combustion Burning Combining with oxygen to produce carbon dioxide and water Burning Methane CH4 + 2O2 CO2 + 2H2O Burning Octane 2C8H18 +25O2 16CO2 + 18H2O Burning Ehtanol C2H5OH + 3O2 2CO2 + 3H2O J Deutsch 2003

Regents Question: 08/02 #21 þ In which reaction is soap a product? (1) addition (2) substitution (3) Saponification (4) polymerization þ J Deutsch 2003