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Ionic Bonds and Ionic Compounds

> Formation of Ionic Compounds

B. Ionic Compounds: composed of cations and anions held together by electrostatic forces called ionic bonds.

1. Are electrically neutral.

a. Total positive charge is equal to the total negative charge.

7.2

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Ionic Bonds and Ionic Compounds

> Formation of Ionic Compounds

2. chemical formula: shows kinds and numbers of atoms in the smallest representative unit of a substance.

a. formula unit: lowest whole-number ratio of ions in an ionic compound.

i. NaCl : sodium chloride.

7.2

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Ionic Bonds and Ionic Compounds

> Use of dot diagrams to predict formula

3. Electron Dot Structure: can be used to determine the chemical formula of an ionic compound.

a. Draw the dot structure for each ion

b. Atoms with less than 4 valence electrons (metals) will give electrons to become cations and atoms with more than 4 valence electrons (non-metals) will receive electrons to become anions.

c. Determine how many of each ion is needed so the total number of electrons received equals the total number of electrons given.

7.2

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Conceptual Problem 7.2

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Conceptual Problem 7.2

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Practice Problems

Problem Solving 7.12 Solve Problem 12 with the help of an interactive guided tutorial.

Guided Practice (now you do it)

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Ionic Bonds and Ionic Compounds

>

Slide 7 of 25

Properties of Ionic Compounds

Properties of Ionic Compounds

What are three properties of ionic compounds?

7.2

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Ionic Bonds and Ionic Compounds

> Properties of Ionic Compounds7.2

4. Properties of Ionic Compounds:

a. Most are crystalline solids at room temperature.

b. Generally have high melting points.

c. Produce specifically shaped crystals.

d. Coordination Number: # ions of __ opposite charge that surround the __ ion in a crystal.

i. NaCl: coordination # of 6.

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Ionic Bonds and Ionic Compounds

> Properties of Ionic Compounds7.2

e. Can conduct an electric current when melted or if dissolved in water.

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Ionic Bonds and Ionic Compounds

> Properties of Ionic Compounds7.2

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Ionic Bonds and Ionic Compounds

> Properties of Ionic Compounds

Simulation 5 Simulate the formation of ionic compounds at the atomic level.

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1. Which chemical formula is incorrect?

a. KF2

b. CaS

c. MgO

d. NaBr

7.2 Section Quiz.

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2. Ionic compounds can conduct an electric current

a. only when melted.

b. when melted or dissolved in water.

c. only when dissolved in water.

d. when solid or melted.

7.2 Section Quiz.

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Slide 14 of 25

3. At room temperature, most ionic compounds are

a. crystalline solids.

b. liquids.

c. gases.

d. soft, low melting-point solids.

7.2 Section Quiz.

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Formation of Ionic Compounds

Animation 8 Take an atomic-level look at the formation of KCl.

GOTO: Unit 7, Section 2, Slide 7

Simulation of the formation of ionic compounds at the atomic level.

GOTO: Unit 7, Section 2, Slide 18