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Introductory Chemistry: A Foundation

FIFTH EDITION

by Ms. GoldamerGreenfield High School

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Nomenclature

Chapter 5

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CHEMISTRY 100Dr. Jimmy HwangSections 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

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OverviewIn Chapter 5, our goals are for the students to:

1. Learn how to name binary compounds of a metal and a nonmetal.2. Learn how to name binary compounds containing only nonmetals.3. Learn the names of common polyatomic ions and how to use

them in naming compounds. 4. Learn how the anion composition determines the acid’s name.5. Learn names of common acids.6. Learn to write the formula of a compound given its name.

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Common Names - Exceptions

• H2O = water, steam, ice

• NH3 = ammonia

• CH4 = methane

• NaCl = table salt

• C12H22O11 = table sugar

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Naming Starts with Classifying Compounds

• Binary Compounds = only 2 elements

• Compounds containing polyatomic ions

• Acids = formula often starts with H

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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

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Binary Ionic

• Made of metal cation and nonmetal anion

• Name by naming the ions

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Metal Cations• Type I

– 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

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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

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Naming CompoundsNaming Compounds

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

Binary Ionic Compounds (Type I):Binary Ionic Compounds (Type I):

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Memorize Table 5.1

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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.

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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 chargesince the total negative charge is -6, the total positive charge is +6

Divide by the number of cationssince there are 2 Au in the formula & the total positive charge is +6, each Au has a +3 charge

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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

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Figure 2.22: The common cations and anions

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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).

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FeCl2 2 Cl- -2 so Fe is +2 iron(II) chloride

FeCl3 3 Cl- -3 so Fe is +3 iron(III) chloride

Cr2S3 3 S2- -6 so Cr is +3 (6/2) chromium(III) sulfide

Principle of Electrical NeutralityThe 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.

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Naming Compounds(continued)

Naming Compounds(continued)

metal forms more than one cation

use Roman numeral in name

PbCl2

Pb2+ is cation

PbCl2 = lead (II) chloride

Binary Ionic Compounds (Type II):Binary Ionic Compounds (Type II):

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QUESTIONWhat is the formula for manganese(IV) oxide? 1) MgO2 2) Mn4O 3) MnO2 4) Mn2O 5) Mg2O

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ANSWER3) MnO2 Section 5.7 Writing Formulas from Names (p. 142) Oxide ion always carries a –2 charge; as the Roman numeral indicates a +4 charge for manganese, there must be two oxides for each manganese cation for electrical neutrality.

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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

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Prefixes

• Drop last “a” in the prefix if the name begins with vowel

octa-8

hepta-7

hexa-6

penta-5

tetra-4

tri-3

di-2

mono-

(not used on first nonmetal)

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PrefixSubscript

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NF3 nitrogen trifluoride

SO2 sulfur dioxide

N2Cl4 dinitrogen tetrachloride

NO2 nitrogen dioxide

N2O dinitrogen monoxide

Molecular Compounds

2.7

TOXIC!

Laughing Gas

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Figure 5.1: A flow chart for naming binary compounds.

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QUESTIONWhat is the formula for sulfur hexafluoride? 1) S3F 2) SF4 3) S6F 4) SF5 5) SF6

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ANSWER5) SF6 Section 5.3 Naming Binary Compounds That Contain Only Nonmetals (Type III) (p. 132) The Greek prefix hexa- indicates six of the fluoride anions are present in this Type III compound. As sulfur contains one prefix, we know there is only one sulfur atom present, and the formula of sulfur hexafluoride must be SF6.

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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

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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

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Patterns for Polyatomic Ions

• -ate ion– chlorate = ClO3

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• -ate ion plus 1 O same charge, per- prefix– perchlorate = ClO4

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• -ate ion minus 1 O same charge, -ite suffix– chlorite = ClO2

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• -ate ion minus 2 O same charge, hypo- prefix, -ite suffix– hypochlorite = ClO-

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Figure 5.2: Overall strategy for naming

chemical compounds.

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Acids

• Contain H+ cation and anion

• Binary acids have H+ cation and a nonmetal anion

• Oxyacids have H+ cation and a polyatomic anion

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Memorize

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Memorize

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Figure 5.3: A flow chart for naming acids. The acid is considered as one or

more H+ ions attached to an anion.

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Memorize

• Acid Anion Name

• HClO4 perchlorate perchloric acid

• HClO3 chlorate chloric acid

• HClO2 chlorite chlorous acid

• HClO hypochlorite hypochlorous acid

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QUESTIONWhat is the formula for copper(I) chloride? 1) CuCl2 2) CuCl 3) CuClO 4) CuClO2 5) CuClO3

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ANSWER2) CuCl Section 5.7 Writing Formulas from Names (p. 142) Since it is known that chloride is always –1, the designation of copper as a +1 ion means this complex must exist with copper and chloride in a 1:1 ratio.

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QUESTIONWhich of the following is named correctly? 1) HCl(aq); hypochlorous acid 2) (NH4)3PO3; ammonium phosphate 3) H2SO3(aq); sulfuric acid 4) Cu(OH)2; copper(II) hydroxide 5) HNO3(aq); nitrous acid

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ANSWER4) Cu(OH)2; copper(II) hydroxide Section 5.7 Writing Formulas from Names (p. 142)

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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

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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