C HAPTER 6 Nomenclature of Inorganic Compounds

6.2 D IATOMIC E LEMENTS

6.3 I ONIC C OMPOUNDS Contain metals and non-metals May be polyatomic Metals are positive (cation) Ag = 1+ Zn = 2+ Al = 3+ Transition metals use Roman Numerals to indicate charge in their name ONLY Non-metals are negative (anion)

6.4 N AMING I ONIC C OMPOUNDS The metal’s name remains the same as the name of the metal The nonmetal’s ending changes to -ide.

6.5 I ONIC C OMPOUNDS WITH P OLYATOMIC I ONS Contain three or more atoms You MUST learn your polyatomic ions in order to recognize the name or symbol of the polyatomic ion when it is in a compound. A metal or ammonium (NH 4 + ) or hydronium (H + ) will be written first, thus indicating an ionic compound

6.5 I ONIC C OMPOUNDS WITH P OLYATOMIC I ONS When writing formulas the charges must balance Subscripts are used for this purpose “criss-crossing” (never write the subscript “one”) If charges are already balanced, do NOT “criss- cross” Use parenthesis around the polyatomic ion when more than one is needed in the formula

6.3 W RITING F ORMULAS FOR I ONIC C OMPOUNDS Writing formulas the charges must balance Subscripts are used If the ions are already balanced, no need to use subscripts. If charges do not balance, the easiest way to balance charges is by “criss-crossing” Do not write the subscript “1” Reduce subscripts

6.4 M OLECULAR (C OVALENT ) C OMPOUNDS Contain ONLY nonmetals NO ions; therefore, NO charges to balance Use the following prefixes to determine the number of atoms needed in the formula or the name of the compound if the formula is given. PrefixNumberPrefixNumber Mono1Hexa6 Di2Hepta7 Tri3Octa8 Tetra4Nona9 Penta5Deca10

6.4 N AMING M OLECULAR C OMPOUNDS Use the prefixes, EXCEPT “mono” for the first atom Use the prefixes for the 2 nd atom ALWAYS Change the ending of the last nonmetal to -ide. The first nonmetal keeps its “original” name.

6.4 W RITING F ORMULAS FOR M OLECULAR C OMPOUNDS Use the prefixes to determine the subscripts on the elements Write the element symbols in the order they appear in the name DO NOT reduce the subscripts

6.6 A CIDS ALL acids contain hydrogen and it is treated as an ion with a +1 charge ALL acids are in an aqueous solution (water) and should be indicated as such by putting (aq) after the formula as a subscript When naming acids, write the word “acid” after the name

6.6 T ERTIARY A CIDS Contain hydrogen + a polyatomic ion Balance the charges of the polyatomic ion and the hydrogen ion Do NOT use the prefix hydro- Change the ending of the polyatomic ion as follows: If the original ending is -ate change to –ic If -ite change to -ous

6.6 B INARY A CIDS Acids that contain hydrogen + a nonmetal Balance the charges of the nonmetal ion and the hydrogen ion (1+) Use the prefix hydro- to indicate that the acid is a binary acid this is the only mention of hydrogen Change the ending of the anion from -ide to -ic

H OMEWORK Required Worksheets

A DDITIONAL P RACTICE Answers to Practice Excercises – Page 118 Review Questions, Paired Excercises, Additional Excercises – Appendix VII