Section 7.2 lecture for Honors & Prep chemistry

1. Bellwork- Ions
Draw a sketch of the periodic table
and label ion charges for groups 1A,
2A, 3A(13), 5A(15), 6A(16), & 7A(17).

2. Lecture 7.2- Ionic Compounds

3. Compounds composed of
cations and anions are called
ionic compounds.

4. Compounds composed of
cations and anions are called
ionic compounds.
Ionic compounds are
electrically neutral.
(positive charges always
equal the negative charges)

5. Aluminum
metal and the
nonmetal
bromine react
to form an
ionic solid,
aluminum
bromide.

6. The electrostatic forces that hold
ions together in ionic compounds
are called ionic bonds.

7. An ionic compound is also called a
salt.

8. An ionic compound is also called a
salt.
Salts contain positive and negative
ions that alternate in a perfect 3D
pattern called a crystal lattice.

9. The
transfer
of an
electron
from Na
Na Cl
to Cl
creates
an
anion
and a
cation. Na+ Cl-

10. The
transfer
of an
electron
from Na
Na Cl
to Cl
creates
an
anion
and a
cation. Na+ Cl-

11. The
transfer
of an Their
electron opposite
from Na charges
Na Cl
to Cl attract
creates them to
an each
anion other.
and a
cation. Na+ Cl-

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

13. •A chemical formula shows the
kinds and numbers of atoms
in the smallest representative
unit of a substance.

14. •A chemical formula shows the
kinds and numbers of atoms
in the smallest representative
unit of a substance.
•A formula unit is the lowest
whole-number ratio of ions in
an ionic compound.

15. NaCl is the chemical formula
for sodium chloride.

16. NaCl is the chemical formula
for sodium chloride.

17. NaCl is the chemical formula
for sodium chloride.

18. NaCl is the chemical formula
for sodium chloride.

19. Determining formulas for ionic
compounds

20. Determining formulas for ionic
compounds
The positive charges must equal
the negative charges, because
the compound is neutral.

21. Determining formulas for ionic
compounds
The positive charges must equal
the negative charges, because
the compound is neutral.
Mg2+ and Cl- make MgCl2
because you need 2 Cl- to cancel
the 2+ charge on Mg

22. What is the formula of a compound
containing ions of Al and O?

23. What is the formula of a compound
containing ions of Al and O?
Al3+ O2-

24. What is the formula of a compound
containing ions of Al and O?
Al3+ O2-
Find the least common multiple!
3+ x 2 = 6+ 2- x 3 = 6-

25. What is the formula of a compound
containing ions of Al and O?
Al3+ O2-
Find the least common multiple!
3+ x 2 = 6+ 2- x 3 = 6-
So you need 2 Al3+ and 3 O2-
Al2O3

26. What is the formula of a compound
containing ions of Al and O?
Al 3+ O2-
Al2O3
The charge on one ion becomes the
subscript for the other ion!

31. Most ionic compounds are
crystalline solids at room
temperature.

32. Most ionic compounds are
crystalline solids at room
temperature.
Ionic compounds have high
melting points.

33. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

34. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

35. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

36. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

37. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

38. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

39. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

40. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

41. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

42. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

43. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

44. The orderly arrangement of component
ions produces the beauty of crystalline
solids.

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

46. • The coordination number of an ion
is the number of ions of opposite
charge that surround the ion in a
crystal.
• In NaCl, each ion
has a coordination
number of 6.

47. • In CsCl, each ion has a coordination
number of 8.
• In TiO2, each Ti4+ ion has a coordination
number of 6, while each O2- ion has a
coordination number of 3.

48. Electricity is the directed
movement of charged particles.
To conduct electricity, a substance or
mixture must contain positive or
negative charges that can move freely.

49. Ionic compounds can conduct
an electric current when
melted or dissolved in water.

50. Ionic compounds can conduct
an electric current when
melted or dissolved in water.

51. 7.2 Section Quiz.
1. Which chemical formula is incorrect?
a. KF2
b. CaS
c. MgO
d. NaBr

52. 7.2 Section Quiz.
1. Which chemical formula is incorrect?
a. KF2
b. CaS
c. MgO
d. NaBr

53. 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.

54. 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.

55. 3. At room temperature, most ionic
compounds are
a. crystalline solids.
b. liquids.
c. gases.
d. soft, low melting-point solids.

56. 3. At room temperature, most ionic
compounds are
a. crystalline solids.
b. liquids.
c. gases.
d. soft, low melting-point solids.