Copyright©2004 by Houghton Mifflin Company. All rights reserved. Introductory Chemistry: A Foundation FIFTH EDITION by Steven S. Zumdahl University of Illinois Copyright©2004 by Houghton Mifflin Company. All rights reserved. 1

Nomenclature Chapter 5 1

CHEMISTRY 100 Dr. Jimmy Hwang Sections 5 and 7 Tu & Th 9:30a. m CHEMISTRY 100 Dr. Jimmy Hwang Sections 5 and 7 Tu & Th 9:30a.m.-10:45a.m. Textbook: Zumdahl, Introductory Chemistry, 5th Edition Office Hours: by appointment 619-421-6700 Ext. 3399 (voicemail) Email: jhwang@swccd.edu

Overview In Chapter 5, our goals are for the students to: 1. Understand why it is important to have a system for naming compounds. 2. Learn how to name binary compounds of a metal and a nonmetal. 3. Learn how to name binary compounds containing only nonmetals. 4. Review the naming of Type I, Type II, and Type III binary compounds. 5. Learn the names of common polyatomic ions and how to use them in naming compounds. 6. Learn how the anion composition determines the acid’s name. 7. Learn names of common acids. 8. Learn to write the formula of a compound given its name.

Common Names - Exceptions H2O = water, steam, ice NH3 = ammonia CH4 = methane NaCl = table salt C12H22O11 = table sugar 2

Naming Starts with Classifying Compounds Binary Compounds = only 2 elements Compounds containing polyatomic ions Acids = formula often starts with H 3

Classifying Binary Compounds Compounds containing a metal and a nonmetal are binary ionic Type I and II Compounds containing two nonmetals Type III Compounds containing H and a nonmetal = Acids 4

Binary Ionic Made of metal cation and nonmetal anion Name by naming the ions 5

Metal Cations Type I Type II Metals that can only have one possible charge Determine charge by position on the Periodic Table Type II Metals that can have more than one possible charge Determine metal cation’s charge from the charge on anion 6

Type I Binary Ionic Compounds Contain Metal Cation + Nonmetal Anion Metal listed first in formula & name Name metal cation first, name nonmetal anion second Simple metal cation name is the metal name simple metals are Groups 1A, 2A and Al, Ga & In Nonmetal anion named by changing the ending on the nonmetal name to -ide 7

CaCl2 = calcium chloride Naming Compounds Binary Ionic Compounds (Type I): 1. Cation first, then anion 2. Monatomic cation = name of the element Ca2+ = calcium ion 3. Monatomic anion = root + -ide Cl = chloride CaCl2 = calcium chloride

Memorize Table 5.1

Principle of Electrical Neutrality The principle that, in any ionic compound, the total positive charge must equal the total negative charge, i.e., a chemical compound must have a net charge of zero.

Determining the Charge on a Cation – Au2S3 using the Principle of Electrical Neutrality Determine the charge on the anion Au2S3 - the anion is S, since it is in Group 6A, its charge is -2 Determine the total negative charge since there are 3 S in the formula, the total negative charge is -6 Determine the total positive charge since the total negative charge is -6, the total positive charge is +6 Divide by the number of cations since there are 2 Au in the formula & the total positive charge is +6, each Au has a +3 charge 9

Type II Binary Ionic Compounds Contain Metal Cation + Nonmetal Anion Metal listed first in formula & name Name metal cation first, name nonmetal anion second Metal cation name is the metal name followed by a Roman Numeral in parentheses to indicate its charge Determine charge from anion charge Common Type II cations in Table 5.2 Nonmetal anion named by changing the ending on the nonmetal name to -ide 8

Figure 2.22: The common cations and anions

Monatomic Ions 2. Transition metal cations (Figure 2.22) Memorize the charge of other metals in Figure 2.8. It is easy to remember the charges of the metal ions in the figures as follows: +1: all alkali metals, Ag+, Cu+, Hg22+ +3: Al3+, Co3+, Cr3+, Fe3+, Mn3+ (AC2FM) +4: Sn4+ , Pb4+ +2: everything else Note that some metals have two charges (Type II).

Principle of Electrical Neutrality The principle that, in any ionic compound, the total positive charge must equal the total negative charge, i.e. a chemical compound must have a net charge of zero. iron(II) chloride 2 Cl- -2 so Fe is +2 FeCl2 iron(III) chloride FeCl3 3 Cl- -3 so Fe is +3 Cr2S3 3 S2- -6 so Cr is +3 (6/2) chromium(III) sulfide

Naming Compounds (continued) Binary Ionic Compounds (Type II):  metal forms more than one cation  use Roman numeral in name PbCl2 Pb2+ is cation PbCl2 = lead (II) chloride

QUESTION

ANSWER Class Prep CD: Table 5.1, Figure 5.1, Figure 5.2

Type III - Binary Compounds of 2 Nonmetals Name first element in formula first, use the full name of the element Name the second element in the formula as if it were an anion However, remember these compounds do not contain ions! Use a prefix in front of each name to indicate the number of atoms Never use the prefix mono- on the first element 10

(not used on first nonmetal) Prefixes octa- 8 hepta- 7 hexa- 6 penta- 5 tetra- 4 tri- 3 di- 2 mono- (not used on first nonmetal) 1 Prefix Subscript Drop last “a” in the prefix if the name begins with vowel 11

Molecular Compounds NF3 nitrogen trifluoride SO2 sulfur dioxide N2Cl4 dinitrogen tetrachloride TOXIC! NO2 nitrogen dioxide N2O dinitrogen monoxide Laughing Gas 2.7

Figure 5.1: A flow chart for naming binary compounds.

QUESTION

ANSWER Class Prep CD: Table 5.3, Table 5.4

Compounds Containing Polyatomic Ions Polyatomic ions are charged entities that contain more than one atom Must memorize name, formula and charge Look for Patterns!! Polyatomic compounds contain one or more polyatomic ions Name polyatomic compounds by naming cation and anion Non-polyatomic ions named like Type I and II Polyatomic Acids contain H+ and a polyatomic anion 12

Patterns for Polyatomic Ions Elements in the same column on the Periodic Table form similar polyatomic ions same number of O’s and same charge ClO3- = chlorate  BrO3- = bromate If the polyatomic ion starts with H, add hydrogen- before the ions name and add 1 to the charge CO32- = carbonate  HCO3- = hydrogen carbonate 13

Patterns for Polyatomic Ions -ate ion chlorate = ClO3- -ate ion plus 1 O  same charge, per- prefix perchlorate = ClO4- -ate ion minus 1 O  same charge, -ite suffix chlorite = ClO2- -ate ion minus 2 O  same charge, hypo- prefix, -ite suffix hypochlorite = ClO- 14

Figure 5.2: Overall strategy for naming chemical compounds.

Acids Contain H+ cation and anion Binary acids have H+ cation and a nonmetal anion Oxyacids have H+ cation and a polyatomic anion 15

Memorize

Memorize

Figure 5. 3: A flow chart for naming acids Figure 5.3: A flow chart for naming acids. The acid is considered as one or more H+ ions attached to an anion.

Memorize Acid Anion Name HClO4 perchlorate perchloric acid HClO3 chlorate chloric acid HClO2 chlorite chlorous acid HClO hypochlorite hypochlorous acid

QUESTION

ANSWER Class Prep CD: Table 5.2, Figure 5.1, Figure 5.2

QUESTION

ANSWER Class Prep CD: Figure 5.1, Figure 5.2, Tables 5.2, 5.4, and 5.6

Writing the Formulas from the Names For Type III compounds, use the prefixes to determine the subscripts For Type I, Type II, polyatomic Compounds and Acids Determine the ions present Determine the charges on the cation and anion Balance the charges to get the subscripts 16

Naming Exercise Al2(C2O4)3 P4O10 Cu(NO2)2 NaMnO4 CS2 Fe2(CrO4)3 Hg2Cl2 NH4BrO2 Ca(ClO4)2 Aluminum oxalate Tetraphosphorous decaoxide Copper(II) nitrite Sodium permanganate Carbon disulfide Iron(III) chromate Mercury(I) chloride Ammonium bromite Calcium perchlorate