Grade 9 -consumer chemistry

1. 1
Writing & Naming
Formulas
of
Ionic & Covalent
Compounds

2. IIA III
A
IVA VA VI
A
VII
A
index
2
Review of the Periodic Table
Periods = number of e- energy levels.
Groups (families) = the number of
valence electrons (A - groups)
IA VIIIA
1
2
3 Transition Metals
4
5
6
7
6
7

3. tight 1
3 Transition Metals
4
5
6
7
6
2
Atomic Radii decreases (more p+)
3
Metals have between 1 and 3 valence e-and
have a loose hold on them.
Nonmetals have between 5 and 7 valence e-and
have a tight hold on them.
Noble Gases
Very
IA VIIIA
IIA IIIA IVA VA VIA VIIA hold on
valence
e-.
Greater hold on valence electrons
7
index

4. IIA III
A
IVA VA VI
A
VII
A
4
Types of Compounds:
Ionic = Metal + Nonmetal
Covalent = 2 Nometals or Metalloid & Nonmetal
Metals Metalloids Nonmetals
IA
VIIIA
1
2
3 Transition Metals
4
5
6
7
6
7

5. Very
An atom consist of a positively charged nucleus
(protons and neutrons) and orbiting electrons.
Not chemically Chemically
5
Chemical Compounds
Important!
Atoms of elements are not chemically stable until they have 8
valence electrons (octet rule).
Atoms gain, lose or share electrons with other atoms to be
come chemically stable( have 8 valence electrons ).
Six valence Eight valence -2
electrons. 8+ electrons. 8+
stable. OxygenAtom stable. Oxide Ion
index

6. Atoms & Ions:
Sodium
Atom 11+
Nitrogen
Atom
7+
Aluminum
Atom
13+
+
1
Sodium
11+
Ion
-3
Nitride
7+ Ion
+3
Aluminum
13+
Ion
6
Not Stable Stable
to become stable will:
Lose 1 e-
Gain 3 e-
Lose 3 e-index

7. 7
Two Types of Compounds
I o n i c - occurswhen a metal loses all
its valence electrons to a nonmetal. The
metal becomes a cation (+ion), while the
nonmetal becomes an anion (- ion).
C o v a l e n t - two nonmetals share
electrons. Neither loses or gains
electrons- they share electrons. Neither
atom becomes an ion.
index

8. Compounds
8
Ionic
Crystalline Lattice
index

9. 2Mg +O2 → 2MgO
12 + 12
+
+
+
8+ 8+
9
Oxidizing Magnesium
Opposite
charges
hold the
compound
together.
+2 -2
Magnesium Atom +Oxygen Atom ➝ Magnesium Ion + Oxide Ion
index

10. 1
-1 Cl
+charges
Crystalline
+ + 17
+
17
+
11
+
11
+
10
Formation of Sodium Chloride
2Na + Cl2 → 2NaCl
Na Opposite
hold the
compound
together.
Lattice
+
-
Sodium Atom + Chlorine Atom ➝ Sodium Ion + Chloride Ion index

11. s
al.
11
Ionic Compound
Contain a metal and a nonmet
The Metal loses e- and becomes a cation (+).
The Nonmetal gains e- and becomes an anion(-).
Metal is listed first, followed by nonmetal.
Change the name of the nonmetal to -ide.
Examples: nitride, sulfide, fluoride, oxide,
bromide, iodide, chloride, telluride, phosphide.
index

12. onmetals gain 1,2 or 3 electrons and become - ions (an
12
Valence (Oxidation Number)
The valence of an elements is the charge an atom takes
when it loses or gains electrons and becomes an ion.
Metal atoms lose 1, 2 or 3 electrons and become + ions (cations)
N ions)
+1
0
+2 +3 -4 -3 -2 -1
Transition Metals
Multiple valences
index

13. 13
The 5 Steps for writing an
ionic compound formula:
(I)Write the symbols of the two elements.
(II)Write the valence of each as superscripts.
(III)Drop the positive and negative signs.
(IV)Crisscross the superscripts so they
become subscripts.
(V)Reduce when possible.
index

14. 14
Formula for boron oxide
1. Write the symbols of the two elements.
B O
index

15. B O
15
Formula for boron oxide
2. Write the valence for each element.
+3 -2
index

16. B O
16
Formula for boron oxide
3. Drop the positive & negative sign.
+ 3 -2
index

17. B O
17
Formula for boron oxide
4. Crisscross the superscripts so they
become subscripts.
3 2
index

18. 18
Formula for boron oxide
4. Crisscross the superscripts so they
become subscripts.
B 2 O3
index

19. 19
Formula for boron oxide
5. Reduce subscripts when possible.
(not possible here)
B 2 O3
index

20. Ba3N2 Reduces to Reduce
20
Examples of Reduction
of Subscripts:
Sr2O2 Reduces to SrO
Al3P3 Reduces to AlP
Pb2O4 Reduces to PbO2
Doesn’t

21. 21
Most Transition metals have two valences.
Roman numerals are used in the name of
the transition metal in the compound
to show the valence on the cation.
Period 4 TransitionMetals
Sc Tl V Cr Mn Fe Co Ni Cu Zn
+3 +4 +5 +6 +4 +2 +2 +2 +2 +2
+3 +4 +3 +6 +3 +3 +3 +1
Examples:
Mn+4 Manganese(IV) Mn+6 Manganese(VI)
Fe +2 Iron(II) Fe+3 Iron(III)
Cu+1 Copper(I) Cu+2 Copper(II)
index

22. +3 Iron(III) Fe
22
Examples of Transition Metals
Iron(II) Fe +2
Copper(I)Cu +1
Copper(II)Cu+2
Manganese(II)Mn+2
Manganese(IV)Mn+4
index

23. 23
Naming binary compounds containing
a transition metal.
formula name
Fe2 O3 Iron(III) oxide
ZnCl 2 Zinc(II) chloride
AgCl Silver(I) chloride
Cu 3 P2 Copper(II) phosphide
PbS2 Lead(IV) sulfide
MnO2 Manganese(IV) oxide

24. In Writing Common names
• The Latin root of the metal is followed by either
Of two suffixes:
-ous for the ion with the LOWER charge.
-ic for the ion with the HIGHER charge.

25. EXAMPLE:
1.Iron (II) chloride
2.Iron (III) chloride -
3.Tin (IV) phosphide -
4.Tin (II) phosphide -

26. EXAMPLE:
1.Iron (II) chloride – Ferrous chloride
2.Iron (III) chloride – Ferric chloride
3.Tin (IV) phosphide – Stannic Phosphide
4.Tin (II) phosphide – Stannous phosphide

27. 24
Polyatomic Ions
-1
hydroxide
Polyatomic (many atom) ions are covalent
molecules with a charge. They behave as
if they were a one-atom ion.
index

28. Ammonium
Hydroxide
Nitrite
Nitrate
SO3
SO4
CO3
PO4
Sulfite
Sulfate
Carbonate
Phosphate
4
OH
NO2
NO3
25
Polyatomic Ions
NH+1 -2
-1 -2
-1 -2
-1 -3
Note: ammonium is the only polyatomic ion with a + charge.
Treat polyatomic ions as you would any ion - crisscross to
determine the formula. The only difference is that when you
have more than one of a specific polyatomic ion in a formula
you must encase it in parenthesis.
index

29. 26
Writing Ternary Formulas
(Ternary compounds have 3 elements in them.)
Cation Anion Compound
+2 -1
Ca NO3 Ca(NO3)2
Mg +2 PO4
Mg3(PO4)2
-3
Ba+2 OH -1 Ba(OH)2
Ba+2 SO-2 Ba SO4
4
As in all ionic compounds you must reduce subscripts, but you
cannot change the formula of the polyatomic ion. You can only
reduce subscripts outside the parenthesis.
index

30. Carbonate CO3
Phosphate PO4
27
Compounds with Polyatomic ions
-2
Sodium carbonate Na2CO3
Calcium carbonate Ca CO3
Aluminum carbonateAl
(CO3)3
2
-3
Sodium phosphateNa3PO4
Calcium phosphate Ca3(PO3 )2
Aluminum phosphateAlPO3
index

31. Families of Oxoanions
• Oxoanions are those in which an element
(usually nonmetal) is bonded to one or more
oxygen atoms.
• There are several families of two or four
oxoanions that differ only in the number of
oxygen atoms.

32. With two oxoanions in the family:
• The ion with more Oxygen atoms takes
the nonmetal root and the suffix -ate
•The ion with less Oxygen atoms takes
the nonmetal root and the suffix -ite

33. With Four Oxoanions in the Family
• The ion with the most O atoms has the prefix
per- , nonmetal root and the suffix -ate
• The ion with one fewer O atoms has just the
root and the suffix -ate
• The ion with two fewer O atoms has just the
root and the suffix –ite
• The ion with the least O atoms has the prefix
hypo-, nonmetal root and the suffix -ite

34. Example:
1. ClO-
2. ClO2
-
-
3. NO2
-
4. NO3

35. ompounds
28
Covalent
Water
Molecule
Hydrogen Oxygen Hydrogen
Atom Atom Atom
index

36. 29
Covalent Compounds
Two nonmetals share electrons so both
have 8 valence electrons. Exception: H
Neither takes on a charge - no valence.
Do not crisscross to determine formula.
Must use prefixes in the name.
Name tells you the formula. Example:
N2O4 is dinitrogen tetroxide.
You cannot reduce the formulas!!!
index

37. 1 1
+ 8+
+
+
30
Reaction between hydrogen + oxygen
2H2 + O2 → 2H2O
1+ 8+
2 Hydrogen Atoms Oxygen Atom Water Molecule 1+
index

38. 32
Covalent Prefixes
Mon - 1
Tetra - 4
Di - 2 Pent- 5
Tri - 3 Hex - 6
Aprefix tells you the number of
atoms of that element
in the compound.

39. 33
Naming
Covalent Compounds
N2O3 Dinitrogen trioxide
CH4 Carbon tetrahydride
PO5 Phosphorus pentoxide
S2F3 disulfur trifluoride

40. form a crystalline
pattern of ions.
34
Ionic and Covalent Structure
Ionic compounds Water
H atoms
lattice - a repeating O atom
Covalent compounds
B+3 ions form individual
N-3 ions molecules that are
not connected to
Boron nitride each other.
index

41. (Metal cation + Nonmetal anion) (Two Nonmetals)
left on the periodic table first, then
Numerals to tell Roman atoms in the compound
the metal.
iron(III) oxide
pent(a)-5, hex-6
Examples:
magnesium nitride dinitrogen trioxide, nitrogen trichloride,
manganese(IV) oxide carbon tetrachloride, dihydrogen oxide beryllium oxide
35
Naming Binary Compounds
Does the compound have a metal?
Yes No
Ionic Covalent
Place metal first followed by nonmetal ending in -ide
Contain a Transition Metal? Place the nonmetal furthest to the
Yes No the other nonmetal ending in -ide.
Use Roman Do not use Use prefixes to tell the number of
the valence of Numerals mon(o)-1, di-2, tri-3, tetr(a)-4,
Examples:
sodium chloride Examples:
copper(II) chloride
aluminum fluoride phosphorus pentoxide, sulfur dioxide
silver(I) chloride
index

42. 36
Name these compounds:
CoF2
cobalt(II) fluoride
PCl 3
Sr3N2
KOH
NH3

43. 36
Name these compounds:
CoF2
cobalt(II) fluoride
PCl 3 phorphorus trichloride
Sr3N2 strontium nitride
KOH potassium hydroxide
NH3 nitrogen trihydride

44. 37
Write formulas for these compounds:
zinc(II) nitride
lithium bromide dinitrogen pentoxide
manganese(IV) sulfide
dihydrogen oxide

45. 37
Write formulas for these compounds:
Zn3N2 zinc(II) nitride
LiBr lithium bromide
N2O5 dinitrogen pentoxide
MnS2 manganese(IV) sulfide
H2O dihydrogen
monoxide

46. 38
Summing up: Ionic
Ionic bonding occurs between a metal and
a nonmetal. Metals lose all their valence e-and
become cations. Nonmetals gain
enoughe- to fill their valence level and
become anions.
Always crisscross valences and reduce to
determine the formulas of ionic compounds
Do not use prefixes in the names.
Ions form a crystalline lattice.
index

47. 39
Summing up: Covalent
Covalent bonding occurs when two nonmetals
share electrons to fill their valence energy
level.
Never use valence to determine the formula -
there isn’t any valence. Since the two atoms
share electrons, they do not take on a
charge.
Always use prefixes in the names.
Atoms combine to form individual molecules.
index

48. 40
And now -
A special type of
Covalent Compound!

49. Polar covalent compounds have a partial charge at each end of the molecule.
because the 8 molecule
H H oxygen nucleus
pull the 10
charged partial
positive. This is
to the oxygen protons of the
it a partial δ - charge that end of the
index
41
Water:APolar Molecule
Awater The hydrogen
molecule is polar δ + charge end of the
protons in the 1+ 1+ becomes
electrons closer O8+ due to the
end of the hydrogen atoms
molecule, giving sticking out near
negative charge. molecule.

50. index
42
Water: APolar Molecule
Explanation:
As you comb your hair you strip electrons off
your hair. Your comb, collecting these electrons,
becomes negatively charged.
when you place a negatively charged comb near a
stream of water, the partial positively charged
end (hydrogen end) of a water molecule are
attracted and pulled towards the comb.

51. a δ+
l δ+
h 0
e
43
δ+ δ -
n
e δ -
g
t
i δ -
v
e
y δ -
c δ+ δ -
a
r
g δ+ δ -
d
δ+ δ -
Why does a
comb attract
a stream of
water?
δ +
H
H
δ -
index

52. - ∞- ∞- - ∞- ∞- - ∞- ∞- - - ∞- ∞-
∞+ ∞+ ∞+ ∞+ ∞+ ∞+ ∞+ ∞+ ∞+ ∞+ ∞+ ∞+ ∞+ ∞+
44
Surface Tension
∞ ∞ ∞ ∞ ∞ ∞-
The partially + charged hydrogen endof a water molecule is
attracted to the partially - charged oxygen end of another
molecule. At the surface this causes surface tension. To enter
the water, one must break apart this attraction.
What animal makes use of surface tension? index

53. a Formula Naming Flowchart
45
Chemical Formulas Index
Types of Compounds
Ionic Compounds Covalent Compounds
Valence Covalent Prefixes
Transition Metals
Lattice & Molecules
Steps in Writing
Polyatomic Ions Polar Molecules
Summing Up
index