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Unit 5BCompounds and Their Bonds

Naming and Writing Ionic Formulas

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Charges of Representative Elements

Transition Metals

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What is this rule?

Correct Na+ and Cl- = NaCl

Mg2+ and Cl- = MgCl2

Al3+ and Cl- = AlCl3

Ca2+ and P3- = Ca3P2

Wrong Na+ and Cl- = Na1Cl1

Mg2+ and Cl- = Mg2Cl1

Al3+ and Cl- = Al3Cl1

Ca2+ and P3- = Ca2P3

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Writing Ionic Formulas

Use Swap & Drop to get subscripts

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Ions Formulas

cation anion

Na+ Cl-

K+ S2-

Mg2+ O2-

Ca2+ I-

Al3+ O2-

What is this rule?

Correct Ca2+ and O2- = CaO

Sn4+ and O2- = SnO2

Mg2+ and S2- = MgS

Wrong Ca2+ and O2- = Ca2O2

Sn4+ and O2- = Sn2O4

Mg2+ and S2- = Mg2S2

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Writing Ionic Formulas

Simplify the ratio of subscripts if possible.

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Learning Check – Page 23

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What is this rule?

Correct Iron (III) & O2- = Fe2O3

Tin (II) & Cl- = SnCl2

Copper (II) & F- = CuF2

Wrong Iron (III) & O2- = Fe3O2

Tin (II) & Cl- = Sn2Cl

Copper (II) & F- = Cu2F

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Writing Ionic Formulas

Transition metals can have more than 1 positive charge.

We use Roman numerals to designate the charge.

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Naming Ionic Compounds with Variable Charge Metals

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Learning Check

Write the formulas and names for compounds of the following ions:

Br− S2− N3−

Na+

Al3+

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Naming Variable Charge Metals

Transition metals with two different ions use a Roman numeral after the name of the metal to indicate ionic charge.

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Learning Check

Select the correct name for each.A. Fe2S3

1) iron sulfide 2) iron(II) sulfide 3) iron(III) sulfide

B. CuO 1) copper oxide 2) copper(I) oxide 3) copper(II) oxide

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Solution

Select the correct name for each.

A. Fe2S3

3) iron (III) sulfide Fe3+ S2-

B. CuO

3) copper (II) oxide Cu2+ O2-