Give the molecular formula for each type of hydrocarbon below if it contains seven carbon atoms, draw one possible isomer and name that isomer. A. An alkane B. An alkene C. An alkyne Functional Groups A functional group is an atom or group of atoms that is responsible for the specific properties of an organic compound A given functional group undergoes the same types of chemical reactions in every molecule in which it is found. Therefore, compounds that contain the same functional group can be classified together. The general formula for a class of organic compounds consists of the functional group and the letter R, which stands for the rest of the compound. Alcohols are organic compounds that contain one or more hydroxyl groups. The general formula for alcohols if R-OH H OH Example: ethanol H—C—C—H H H Alcohols are often used as alternative fuels, ethanol for example. Alcohols can be classified by the number of carbons bonded to the carbon which holds the hydroxyl group. Primary alcohols have 1 carbon bonded to the alcohol carbon. Example—1-propanol Secondary alcohols have 2 carbons bonded to the alcohol carbon. Example—2-propanol Tertiary alcohols have 3 carbons bonded to the alcohol carbon. Example—2-methyl-2-butanol The name of the alkane chain loses the -e and adds –ol. A number is used to indicated the carbon position of the hydroxyl group. If more than one hydroxyl group is present, use the ending, -diol, -triol, etc. Name: H3C-CHOH-CHOH-CH3 Alkyl halides are organic compounds in which one or more halogen atoms, fluorine, chlorine, bromine, or iodine, are substituted for one or more hydrogen atoms in a hydrocarbon. Since X is often used to represent a halogen, the general formula for alkyl halides is R-X Chlorofluorocarbons, better known as CFC’s have been used in the past as liquid refrigerants and in aerosol cans. These were found to deplete the ozone because they would react with O3 and convert it to diatomic oxygen, O2. Another alkyl halide is Teflon. C2F4 is joined in long chains to make the Teflon coating. It has a low coefficient of friction which makes it ideal for a “non-stick” coating. You have already learned how to name alkyl halides. Halogenated Hydrocarbons Worksheet Ethers are organic compounds in which two hydrocarbon groups are bonded to the same atom of oxygen. The hydrocarbon groups may be the same or different. The general formula is R—O—R’. Example: CH3—O—CH3 Dimethyl ether Ethers are often used as organic solvents since they are relatively unreactive. Simply name the two hydrocarbon groups then add the term ether. What would be the formula for methyl ethyl ether? What would be the name of H3C-CH2-CH2-OCH2-CH2-CH3? Do the first 7 rows of the Functional Groups Worksheet Finish first 7 rows of Functional Groups Worksheet Read Text 733-734 Text 734 #1-5 Write the general formula for the following and give one example of each: a) alcohol b) ether c) alkyl halide Aldehydes and ketones contain the carbonyl group. Aldehydes have the carbonyl group attached to a carbon atom at the end of a chain. Ketones have the carbonyl group attached to carbon atoms within the chain. General Formula for Aldehydes and Ketones Aldehydes and ketones are often responsible for odors and flavors. See Figure 14 Page 733 Since the carbonyl group is always attached to the 1st carbon, we do not use numbers to indicate the position of the carbonyl group when naming aldehydes. Drop the ending –ane, -ene or -yne from the hydrocarbon and add –al What is the structural formula for butanal? Name this one Drop the –e from the parent chain and add -one. You must use a position number for the carbonyl group. Carbonyl groups have priority for numbering. What is the structure for 2-hexanone? Name this one: Amines are organic compounds that can be considered to be derivatives of ammonia, NH3. Because the ammonia atoms have an unshared electron pair, they will act as weak bases in aqueous solutions. The general formula is R-N-R” R’ Primary Amines—drop the –e of the parent chain, add –amine. Secondary Amines—drop the –e of the parent chain, add amine. Use N-to designate that the second alkyl group is present on the nitrogen atom. Example: 2-propanamine Example: N-methyl-1-propanamine Tertiary Amines are named like secondary, but use two N’s to designate the second and third alkyl group. Example: N, N-dimethylpropanamine Carboxylic acids are organic compounds that contain the carboxyl functional group. General Formula Carboxylic acids, like inorganic acids, react to lose a H+ and become negatively charged in water. They are weak acids. Acetic acid is a carboxylic acid as is the citric acid found in many fruits. Since the carboxyl group is always at the end of the chain, there is no need to indicate the position number of the group. It is always on the 1st carbon. Drop the ending –e and add –oic acid. What would be the structure for butanoic acid? Name this one: Esters are organic compounds that have carboxylic acid groups in which the hydrogen of the hydroxyl group has been replaced by an alkyl group. General Formula Esters are derivatives of carboxylic acids. Many occur naturally in fats and oils. Low molecular weight esters are found in essential oils and pheremones. First name the part that is the alkyl group, then the acid using an –oate ending. What would be the structure for methyl propanoate? Name this: Complete the rest of the table. Finish Functional Groups Worksheet Complete Practice with Functional Groups Worksheet #1-8 Functional Groups Quiz—Friday 5/28