Unit VII Compound Formula Writing and Nomenclature Review Sheet. Chapter 6: Basic Naming & Formula Writing

Transcription

1 Unit VII Compound Formula Writing and Nomenclature Review Sheet Chapter 6: Basic Naming & Formula Writing 1. Distinguish among: a. Atoms b. Molecules: combinations of covalently bonded nonmetals c. Formula units: combinations of metals & nonmetals in an IONIC bond. 2. You should be able to briefly explain how a compound obeys the Law of Definite Proportions.; the same holds true for the Law of Multiple Proportions. 3. Nomenclature is broken down into two groups: a. IONIC: Metals: i. Simple metals from Groups 1A, 2A, and 3A retain the name of the element when combined with a nonmetal ii. For the Transition metals that have multiple charges; i.e. Fe +2, Fe +3, Pb +2, Pb +4, etc, be able to use the Stock system to designate the charge of the metal ion, AS WELL as the Classical system, for those transition metals that were given on the Periodic Table & Study Guide. iii. Polyatomics that behave like a metal: there were two that I gave you, Ammonium (NH + 4 ), and Hydronium (H 3 O + ) Nonmetals: i. Simple nonmetals from groups 5A, 6A, and 7A; simply drop the ending of the nonmetal name, and add ide to the name (i.e. sulfur becomes sulfide). ii. Polyatomics that behave like nonmetals: here, you ll need to remember the entire list that I gave you. You can use the Periodic Table pneumonic to remember all of the ATE polyatomics (i.e for the oxygen number, and for the negative charge of the group). b. COVALENT: i. Unlike ionic naming, where the name implies the combination of ions (i.e. Iron (III) oxide implies a combination of Fe +3 and O -2, to form Fe 2 O 3 ), covalent molecules require the author to tell exactly how many atoms of each element are present. The element on the left retains its name, and the element on the right gets shortened, and converted to an -ide ending. Mono is never used on the leftmost atom, and when using the prefixes, two vowels are avoided. For example, N 2 O 4 is dinitrogen tetroxide 4. You will be expected to go from the name, to the formula, and vice versa. 5. Identify by name and write formulas for common acids. There are two types of Acids: a. Simple Binary Acids: named by using the word Hydro-, plus the name of the nonmetal, shortened with ic acid. For example, HCl is hydrochloric acid, HBr is hydrobromic acid, etc. b. Oxyacids: Hydro is not used. Instead, the name of the polyatomic is shortened to ic acid for the ate ions, and ous acid for the ite ions. For example: i. HNO 3 (includes the nitrate ion): Nitric Acid ii. HNO 2 (includes the nitrite ion): Nitrous Acid

2 Chapter 25: Organic Nomenclature 6. Alkanes: Saturated Hydrocarbons with a General Formula of C n H 2(n)+2 a. Look for the longest continuous chain, and name the parent alkane according to the names given for 1 carbon (methane) through 10 carbons (decane). b. Identify the side alkyl (or aliphatic) groups, as well as halogen side groups. c. Number the side groups so that you have the lowest possible combinations of numbers. d. When the same group appears multiple times, use di, tri tetra, etc. For example, dimethyl, triethyl, etc. e. When writing the name, place the number(s) (the address) of the side group(s) right before the group s name. Write the names, from left to right, in alphabetical order. The halogen groups take priority when numbering the carbons, so the halogen should always have the lowest number, relative to the alkyl neighbors. f. Here s an example: 2-chloro-4-methyl pentane: g. When there s a tie between groups of similar priority, the side group with the lowest alphabetical name gets the priority: 2-bromo-4-chloro-pentane h. Remember, Isomers are molecules that have the same molecular formula, but different structural formulas. Butane, for example, has 2 possible isomers, while pentane has 3. I would suggest that you know how to write/id these. 7. Cycloalkanes: Saturated Hydrocarbons with a General Formula of C n H 2(n) a. Name the cyclic hydrocarbon according to the number of carbons in the chain. b. Name the side groups by giving the group with the most priority (i.e. halogens, then alphabetical) the number 1, and count around the ring so that you have the lowest number combination: 8. Alkenes: An Unsaturated Hydrocarbon with a General Formula of C n H 2(n) a. Look for the longest continuous chain that contains the double bond. Remember, the chain MUST contain the double bond. b. Name the longest chain with the same prefix as the alkane, except now the ending is ene to indicate that there is a double bond. The location of the double bond is given as a number directly before the parent chain s name: CH 2 =CHCH 2 CH 3 is 1-butene c. Identify and number the side groups, as before, except this time, the Double Bond gets priority and should have the lowest possible number: i.e. 3-methyl-4,4,-difluoro-1-butene

3 d. Cis & Trans Isomers: Unlike the single bond, double bonds do not rotate, and are fixed. This creates structures that are related in what are called cis and trans isomers; cis indicating the SAME side, while trans represents opposite sides: 9. Alkynes: An Unsaturated Hydrocarbon with a General Formula of C n H 2(n)-2 a. Look for the longest continuous chain that contains the triple bond. Remember, the chain MUST contain the triple bond. b. Name the longest chain with the same prefix as the alkane, except now the ending is yne to indicate that there is a double bond. The location of the double bond is given as a number directly before the parent chain s name: CH=CCH 2 CH 3 is 1-butyne c. Identify and number the side groups, as before, except this time, the Double Bond gets priority and should have the lowest possible number: is 3-methyl-4,4,-difluoro-1-butyne 10. Aromatics: Hydrocarbons that contain a Benzene Ring, which resembles cyclohexane, with an additional 6 resonating pi electrons (C 6 H 6 ) a. Aromatic compounds are named with benzene as the parent chain, with the side groups named in front of the name benzene.

4 b. No number is needed for mono-substituted benzene since all the ring positions are identical. Methylbenzene Chlorobenzene c. When two groups are attached to benzene, the ring is numbered to give the lower numbers to the side groups. The prefixes ortho (1,2), meta (1,3-) and para (1,4-) are also used. d. Here are some common aromatic compounds that you should know: 11. Functional Groups: you should be able to identify the basic structures/functional groups of the following Organic Compounds:

5 12. Describe the characteristics of the formation of a polymer. Some common polymers to know are: