Chapter 5

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Nomenclature

Chapter 5

1

Common Names - Exceptions

H

2

O = water, steam, ice

NH

3

= ammonia

CH

4

= methane

NaCl = table salt

C

12

H

22

O

11

= table sugar

2

Naming Starts with Classifying Compounds

Binary Compounds = only 2 elements

HCl NaBr Fe

2

O

3

CH

4

Compounds containing polyatomic ions

(NH

4

)

3

PO

4

Ca(MnO

4

)

2

Acids = formula often starts with H

HCl H

2

SO

4

HNO

3

3

Classifying Binary Compounds

Compounds containing a metal and a nonmetal are binary ionic

Type I = metal cation can only have one charge

Type II = metal cation can have different charges

Compounds containing two nonmetals

– Type III

• Compounds containing H and a nonmetal = Acids

4

Metal Cations

Type I

Metals that can only have one possible charge

– Determine charge by position on the Periodic

Table

AlCl

3

, BaO, Ca

3

N

2

Type II

Metals that can have more than one possible charge

– Determine metal cation’s charge from the charge on anion

FeCl

2

, FeCl

3

CuI, CuI

2

5

Table 5.1: Common Simple Cations and Anions

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, Ag, Ga &

In

Nonmetal anion named by changing the ending on the nonmetal name to ide

7

Type I Binary Ionic Compound Examples

CaS

Calcium sulfide

AlCl

3

Aluminum chloride

Rb

2

O

– Rubidium oxide

– SrI

2

Strontium iodide

8

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

9

Ion

Fe 3+

Fe 2+

Cu 2+

Cu +

Co 3+

Co 2+

Sn 4+

Sn 2+

Pb 4+

Pb 2+

Hg 2+

Hg

2

2+

Systematic Name Old Name

Iron(III)

Iron(II)

Copper(II)

Copper(I)

Cobalt(III)

Cobalt(II)

Tin(IV)

Tin(II)

Lead(IV)

Lead(II)

Mercury(II)

Mercury(I)

Ferric

Ferrous

Cupric

Cuprous

Cobaltic

Cobaltous

Stannic

Stannous

Plumbic

Plumbous

Mercuric

Mecurous

10

Determining the Charge on a Cation – Au

2

S

3

Determine the charge on the anion

Au

2

S

3 is -2

- the anion is S, since it is in Group 6A, its charge

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

Au

2

S

3

= gold(III) sulfide

11

Type II Binary Ionic Compound Example

CuCl

– Copper(I) chloride

– CoBr

2

Cobalt(II) bromide

PbO

2

– Lead(IV) oxide

– Hg

2

S

Mercury(I) sulfide

12

Figure 5.1: A flow chart for naming binary compounds.

13

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 monoon the first element

14

Prefixes

Subscript

1

5

6

7

8

2

3

4

Prefix mono-

(not used on first nonmetal) ditritetrapentahexaheptaocta-

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

15

Type III Binary Compounds

BF

3

– Boron trifluoride

– NO

Nitrogon monoxide

N

2

O

5

– Dinitrogen pentoxide

– CCl

4

Carbon tetrachloride

16

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

17

Table 5.4: Names of Common Polyatomic Ions

18

Compounds with Polyatomic Ions

• Na

2

SO

4

Sodium sulfate

KMnO

4

Potassium permanganate

KH

2

PO

4

Potassium dihydrogen phosphate

(NH

4

)

2

Cr

2

O

7

Ammonium dichromate

• Fe(NO

3

)

3

Iron(III) nitrate

Cu(NO

2

)

2

Copper(II) nitrite

Mn(OH)

Manganese(II) hydroxide

CsClO

4

Cesium perchlorate

19

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

ClO

3

= chlorate

BrO

3

= bromate

If the polyatomic ion starts with H, add hydrogen - before the ions name and add 1 to the charge

CO

3

2= carbonate

HCO

3

= hydrogen carbonate

20

Patterns for Polyatomic Ions

-ate ion

– chlorate = ClO

3

-

• -ate ion plus 1 O

 same charge, perprefix

– perchlorate = ClO

4

-

• -ate ion minus 1 O

 same charge, ite suffix

– chlorite = ClO

2

-

• -ate ion minus 2 O

 same charge, hypoprefix, ite suffix

– hypochlorite = ClO -

21

Acids

Contain H + cation and anion

Binary acids have H + cation and a nonmetal anion

Oxyacids have H + cation and a polyatomic anion

22

Table 5.5: Names of Acids that Do Not Contain

Oxygen

23

Acid

HNO

3

HNO

2

H

2

SO

4

H

2

SO

3

H

3

PO

4

HC

2

H

3

O

2

Name

Nitric acid

Nitrous acid

Sulfuric acid

Sulfurous acid

Phosphoric acid

Acetic Acid

24

Figure 5.3:

A flow chart for naming acids

25

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

26

• Potassium hydroxide

KOH

Sodium carbonate

• Na

2

CO

3

• Nitric acid

HNO

3

Cobalt(II) nitrate

Co(NO

3

)

2

• Diphosphorous pentoxide

P

2

O

5

Ammonium sulfate

• (NH

4

)

2

SO

4

• Disulfur dichloride

S

2

Cl

2

Rubidium peroxide

Rb

2

O

2

27

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