Chapter 4 “Chemical Names and Formulas” Modified and adapted from Pre-AP Chemistry Charles Page High School Stephen L. Cotton H2OH2O

Section 4.5 Naming and Writing Formulas for Organic Compounds l OBJECTIVES: –Interpret the prefixes in the names of Organic compounds in terms of their chemical formulas.

Section 4.5 Naming and Writing Formulas for Organic Compounds l OBJECTIVES: –Interpret the functional groups in the names of organic compounds in terms of their chemical formulas.

Section 4.5 Naming and Writing Formulas for Organic Compounds l OBJECTIVES: –Apply the rules for naming and writing formulas for organic compounds.

Molecular Compounds –Organic hydrocarbons –always have C & usually H, O, S, or N in a compound

Organic Compounds l Organic Compounds - any covalently bonded compound containing carbon (except carbonates and oxides) l Functional group - a specific arrangement of atoms in an organic compound that is capable of characteristic chemical reactions.

Hydrocarbons l Hydrocarbons are the simplest organic compounds. l They contain only carbon and hydrogen l They can be straight-chain, branched chain, or cyclic molecules. l Carbon must form 4 bonds

Naming Hydrocarbons l Alkanes - contain only single covalent bonds l Alkenes - contain one or more carbon- carbon double bond l Alkynes - contain one or more carbon- carbon triple bond

Naming Hydrocarbons C x H (2x-2) Alkyne

Organic Prefixes # of C-atoms Prefix 1 meth 2 eth 3 pro 4 but 5 pent # of C-atoms Prefix 6 hex 7 hept 8 oct 9 non 10 dec

Simple Alkanes

Functional Groups

ClassGroupEnding Halides-X (F, Cl, Br, I)goes in front Alcohol-OH-ol Carboxylics-COOH-oic Acid Amine-NH 2 Amino or Amine

Examples of Functional Group Propanol:3 C’s, single & alcohol C-C-C-OH Ethanoic Acid: 2 C’s, single, Carboxylic C-COOH Methylamine: 1 C, 1 Amine C-NH 2 Ethyl Aldehyde:2 C’s, 1 aldehyde C-CHO

Section 4.6 The Laws Governing Formulas and Names l OBJECTIVES: –Define the laws of definite proportions and multiple proportions.

Section 4.6 The Laws Governing Formulas and Names l OBJECTIVES: –Apply the rules for naming chemical compounds by using a flowchart.

Section 4.6 The Laws Governing Formulas and Names l OBJECTIVES: –Apply the rules for writing the formulas of chemial compounds by using a flowchart.

Some Laws: l 1. Law of Definite Proportions- in a sample of a chemical compound, the masses of the elements are always in the same proportions. l H 2 O (water) and H 2 O 2 (hydrogen peroxide)

Some Laws: l 2. Law of Multiple Proportions- Dalton stated that whenever two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.

Same mass of oxygen - Page 275

Helpful to remember In an ionic compound, the net ionic charge is zero (criss-cross method) 2. An -ide ending generally indicates a binary compound 3. An -ite or -ate ending means there is a polyatomic ion that has oxygen 4. Prefixes generally mean molecular; they show the number of each atom

Helpful to remember A Roman numeral after the name of a cation is the ionic charge of the cation l Use the handout sheets provided by your teacher!