Transcript Ionic Bonds and Ionic Compounds

7.2
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.
Slide
1 of 25
© Copyright Pearson Prentice Hall
7.2
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.
Slide
2 of 25
© Copyright Pearson Prentice Hall
7.2
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. 3 Slide
of 25
© Copyright Pearson Prentice Hall
Conceptual Problem 7.2
Slide
4 of 25
© Copyright Pearson Prentice Hall
Conceptual Problem 7.2
Slide
5 of 25
© Copyright Pearson Prentice Hall
Practice Problems Guided Practice (now you do it)
Problem Solving 7.12 Solve Problem
12 with the help of an interactive
guided tutorial.
Slide
6 of 25
© Copyright Pearson Prentice Hall
7.2
Ionic Bonds and Ionic
Compounds
> Properties of Ionic Compounds
Properties of Ionic Compounds
What are three properties of ionic
compounds?
Slide
7 of 25
© Copyright Pearson Prentice Hall
7.2
Ionic Bonds and Ionic
Compounds
> Properties of Ionic Compounds
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.
Slide
8 of 25
© Copyright Pearson Prentice Hall
7.2
Ionic Bonds and Ionic
Compounds
> Properties of Ionic Compounds
e. Can conduct an electric current when
melted or if dissolved in water.
Slide
9 of 25
© Copyright Pearson Prentice Hall
7.2
Ionic Bonds and Ionic
Compounds
> Properties of Ionic Compounds
Slide
10 of 25
© Copyright Pearson Prentice Hall
Ionic Bonds and Ionic
Compounds
> Properties of Ionic Compounds
Simulation 5 Simulate the formation of ionic
compounds at the atomic level.
Slide
11 of 25
© Copyright Pearson Prentice Hall
7.2 Section Quiz.
1. Which chemical formula is incorrect?
a.
KF2
b.
CaS
c.
MgO
d.
NaBr
Slide
12 of 25
© Copyright Pearson Prentice Hall
7.2 Section Quiz.
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.
Slide
13 of 25
© Copyright Pearson Prentice Hall
7.2 Section Quiz.
3. At room temperature, most ionic compounds
are
a.
crystalline solids.
b.
liquids.
c.
gases.
d.
soft, low melting-point solids.
Slide
14 of 25
© Copyright Pearson Prentice Hall
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
Slide
15 of 25
© Copyright Pearson Prentice Hall