1. More Nomenclature

2. What are covalent bonds? Result from a sharing of electrons between participants

3. Covalent bonding Tight sharing of electron pairs between 2 or more elements Molecule – a neutral group of atoms that are held together by covalent bonds. Molecular compound – a chemical compound whose simplest units are molecules

4. Naming Binary Molecular Compounds Less-electronegative atom Listed first Prefixes are required if more than one atom exists More-electronegative atom Listed second Prefix always required Ends in “ide” “o” or “a” of prefix is dropped with “oxide” Examples CO – carbon monoxide SCl 4 – sulfur tetrachloride P 2 S 5 – diphosphorus pentasulfide SPELLING COUNTS!

5. Prefixes Number of AtomsPrefix 1mono- 2di- 3tri- 4tetra- 5penta- 6hexa- 7hepta- 8octa- 9nona- 10deca-

6. Molecular formula indicates the actual number and types of atoms in a molecule Empirical formula indicates only the relative number of atoms of each type. The subscripts are always the smallest possible ratios.

7. ACIDS Binary – only 2 elements (usually H and halogen) Oxyacid – hydrogen, oxygen and 3 rd element

8. Nomenclature of Acids No oxygen in the anion: Prefix: hydro- Ending: -ic acid HCl – hydrochloric acid HCN – hydrocyanic acid Oxyacids (oxygen in the anion): No prefix If the anion ends in –ate, the acid ends in –ic acid If the anion ends in –ite, the acid ends in –ous acid HC 2 H 3 O 2 – acetic acid HNO 2 – nitrous acid

9. Simple organic compounds The study of compounds of carbon is called organic chemistry. Compounds that contain carbon and hydrogen – often with oxygen, nitrogen and other elements are organic compounds.

10. Alkanes Compounds that contain only carbon and hydrogen and single bonds. Named by number of carbons

11. Alkanes 1- methane 2 – ethane 3 – propane 4 – butane 5 – pentane 6 – hexane 7 – heptane 8 – octane

12. Alcohols – OH functional group If OH replaces one of the H’s in an alkane it becomes an alcohol. Methanol Ethanol Propanol Butanol

13. Alcohol naming Use a number prefix in front of an alcohol to indicate which carbon the OH is coming off of. 1-propanol 2-propanol