Section 2.8

Naming Simple Compounds

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04/22/23Chemistry

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Vocabulary - ReviewVocabulary - ReviewQ: What is a cation?A: A positive ion formed by a metal

Examples: Na+ Ca 2+ Al 3+

Q: What is an anion?A: A negative ion formed by a nonmetal.

Examples: H- F- O 2- P 3-

Q: What is a polyatomic ion?A: A group of charged atoms NH4

+ SO42-

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Section 2.8

Naming Simple Compounds

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Ionic CompoundsAttraction between + ions and - ions

Electrons go from metals to nonmetals

electron transfer

metal nonmetal ion+ ion–

Electrons lost = Electrons gain

NOTE: the net charge on the compound is zero

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Section 2.8

Naming Simple Compounds

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Formation of Ionic Compounds

Section 2.8

Naming Simple Compounds

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Ionic Bonding

What happens when an atom of sodium reacts with an atom of chlorine?

Na Na+ + 1e-

Cl + 1e- Cl-

Na + Cl + 1e- Na+Cl- + 1e-

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Section 2.8

Naming Simple Compounds

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Ionic Bonding

We write Na+Cl- as simply NaCl

• The ionic compound is neutral – this means the net (overall) charge is = 0.

• Now let’s try for cesium reacting with sulfur.

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Section 2.8

Naming Simple Compounds

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Ionic Bonding

Cs Cs+ + 1e-

S + 2e- S2-

Cs + S + 2e- Cs+S2- + 1e-

This equation is not balanced. What must be done to correct this?

Solution:

1. Write the symbol for each ion present

2.Make sure you include the charge of each ion 6

Section 2.8

Naming Simple Compounds

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Writing a Formula

Write the formula for the ionic compound that will form between Ba2+ and Cl.

Solution:

1. Balance charge with + and – ions

2. Write the positive ion of metal first, and the

negative ion Ba2+ Cl

3. Write the number of ions needed as

subscripts BaCl2 (NOTE WE CRISSCROSSED THE CHARGES)

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Section 2.8

Naming Simple Compounds

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Ionic Compounds--Example: Sodium and oxygen react

1. You have to balance the charges. 2. You do this by criss-crossing the value of the charge

(not the + or -)

Sodium oxideNa+ O2-

Na2O we do not write the 1 as a subscript

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Section 2.8

Naming Simple Compounds

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Ionic Compounds

Lithium iodide

Li+ I –

LiI

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Section 2.8

Naming Simple Compounds

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Ionic Compounds

Magnesium oxide

Mg2+ O2-

Mg2O2 MUST be reduced to MgO

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Section 2.8

Naming Simple Compounds

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Ionic Compounds

Let’s try a few:

Barium nitride

Ba3N2

Aluminum oxide

Al2O3

Cesium iodideCsI

Sodium fluorideNaF

Strontium bromide

SrBr2

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Section 2.8

Naming Simple Compounds

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Learning Check

Write the correct formula for the compounds containing the following ions:

A. Na+, S2-

B. Al3+, Cl-

C. Mg2+, N3-

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Section 2.8

Naming Simple Compounds

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Solution

A. Na+, S2-

Na2S

B. Al3+, Cl-

AlCl3

C. Mg2+, N3-

Mg3N2

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Section 2.8

Naming Simple Compounds

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• Binary Compounds Composed of two elements Ionic and covalent compounds included

• Binary Ionic Compounds Metal—nonmetal

• Binary Covalent Compounds Nonmetal—nonmetal

Naming Compounds

Section 2.8

Naming Simple Compounds

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• Binary Compounds Composed of two elements

• Binary Ionic Compounds Metal—nonmetal

• Binary Covalent Compounds Nonmetal—nonmetal

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• Binary ionic compounds contain positive cations and negative anions. Type I compounds

• Metal present forms only one cation.

Type II compounds • Metal present can

form 2 or more cations with different charges.

Section 2.8

Naming Simple Compounds

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1. Contain 2 different elements

2. The cation is always named first and the anion second.

2. A cation has same name as element.Examples: Ca2+ calcium

Al3+ aluminum

Na + sodium

3. A anion has the same name as the element name with adding –ide to the end.

Examples: Cl - chloride

S2- sulfide

P3- phosphide

Binary Ionic Compounds (Type I monatomic cations & anions)

Section 2.8

Naming Simple Compounds

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Common Simple Cations and Anions

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Naming Simple Compounds

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1. The cation is always named first and the anion second.

2. A simple cation takes its name from the name of the element.

3. A simple anion is named by taking the first part of the element name (the root) and adding –ide.

Rules for Naming Type I Ionic Compounds

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Naming Simple Compounds

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• Examples:

KCl Potassium chloride

MgBr2 Magnesium bromide

CaO Calcium oxide

Binary Ionic Compounds (Type I)

Section 2.8

Naming Simple Compounds

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Ionic Compounds

Now let us put it all together:

Na3N

Cation: sodium

Anion: nitride

Compound: Sodium nitride

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Ionic Compounds

BaO

Cation: barium

Anion: oxide

Compound: barium oxide

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Section 2.8

Naming Simple Compounds

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Naming Binary Ionic Compounds (Type I)

SUMMARY - Name the metal first, then the nonmetal with ending changed to -ide.

Examples:

NaCl sodium chloride

ZnI2 zinc iodide

Al2O3 aluminum oxide

KCl Potassium chloride

MgBr2 Magnesium bromide

CaO Calcium oxide23

Section 2.8

Naming Simple Compounds

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Exercise

What is the name of the compound SrBr2?

a) strontium bromine

b) sulfur bromide

c) strontium dibromide

d) strontium bromide

Section 2.8

Naming Simple Compounds

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Learning Check Complete the names of the following type I binary compounds:

Na3N sodium ________________

KBr potassium ________________

Al2O3 aluminum ________________

MgS _________________________

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Section 2.8

Naming Simple Compounds

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Solution Complete the names of the following binary compounds:

Na3N sodium nitride

KBr potassium bromide

Al2O3 aluminum oxide

MgS magnesium sulfide

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Naming Simple Compounds

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Binary Ionic Compounds (Type II)

• Metals in these compounds can form more than one type of positive charge.

• Charge on the metal ion must be specified.

• Roman numeral indicates the charge of the metal cation.

• Transition metal cations usually require a Roman numeral.

Section 2.8

Naming Simple Compounds

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• Metals in these compounds form more than one type of positive charge.

• Charge on the metal ion must be specified.• Roman numeral indicates the charge of the metal

cation.• Transition metal cations that form 2 or more

positive ions require a Roman numeral.

Binary Ionic Compounds (Type II)

1+ or 2+ ____________________ 2+ or 3+

Cu+, Cu2+ Fe2+, Fe3+

copper(I) ion iron(II) ion

copper (II) ion iron(III) ion

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Naming Simple Compounds

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Common Type II Cations

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1. The cation is always named first and the anion second.

2. Because the cation can assume more than one charge, the charge is specified by a Roman numeral in parentheses.

Rules for Naming Type II Ionic Compounds

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Naming Simple Compounds

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• Examples:

CuBr Copper(I) bromide

FeS Iron(II) sulfide

PbO2 Lead(IV) oxide

Binary Ionic Compounds (Type II)

Section 2.8

Naming Simple Compounds

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Binary Ionic Compounds (Type II)

Use a roman number after the name of a metal that forms two or more ions (note compound is neutral)

Example:

FeCl3 (Fe3+) iron (III) chloride

CuCl (Cu+ ) copper (I) chloride

SnF4 (Sn4+) tin (IV) fluoride

PbCl2 (Pb2+) lead (II) chloride

Fe2S3 (Fe3+)iron (III) sulfide

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Section 2.8

Naming Simple Compounds

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Exercise

What is the name of the compound CrO2?

a) chromium oxide

b) chromium(II) oxide

c) chromium(IV) oxide

d) chromium dioxide

Section 2.8

Naming Simple Compounds

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Exercise

What is the correct name of the compound that results from the most stable ion for sulfur and the metal ion that contains 24 electrons?

a) iron(III) sulfide

b) chromium(II) sulfide

c) nickel(III) sulfate

d) iron(II) sulfide

Section 2.8

Naming Simple Compounds

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Learning Check Complete the names of the following binary

compounds with variable metal ions:

FeBr2 iron (_____) bromide

Cu2O copper (_____) oxide

SnCl4 ___(_____ ) ______________

Fe2O3 ________________________

CuS ________________________35

Section 2.8

Naming Simple Compounds

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Solution Complete the names of the following binary

compounds with variable metal ions:

FeBr2 iron ( II ) bromide

Cu2O copper ( I ) oxide

SnCl4 tin (IV) chloride

Fe2O3 iron (III) oxide

CuS copper (II) sulfide36

Section 2.8

Naming Simple Compounds

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Learning Check

Name the following compounds:A. CaO

B. SnCl4

C. Co2O3

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Section 2.8

Naming Simple Compounds

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Solution Name the following compounds:

A. CaO calcium oxide

B. SnCl4 tin(IV) chloride

C. Co2O3 cobalt (III) oxide

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Section 2.8

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• Polyatomic ions are charged entities composed of several atoms bound together.

• They have special names and must be memorized. (see Table 2.5 on pg. 62 in text).

• Examples of compounds containing polyatomic ions:

NaOH Sodium hydroxide

Mg(NO3

)2

Magnesium nitrate

(NH4

)2

SO4

Ammonium sulfate

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Naming Simple Compounds

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Names of Common Polyatomic Ions

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• Naming ionic compounds containing polyatomic ions follows rules similar to those for binary compounds. Ammonium acetate

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NaOH Sodium hydroxide

Mg(NO3)2 Magnesium nitrate

(NH4)2SO4 Ammonium sulfate

FePO4 Iron(III) phosphate

Examples

Section 2.8

Naming Simple Compounds

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Exercise

What is the name of the compound KClO3?

a) potassium chlorite

b) potassium chlorate

c) potassium perchlorate

d) potassium carbonate