3.1
Identify the following combinations of elements in a compound as ionic or molecular.
(a) nitrogen and oxygen
(b) potassium and oxygen
(c) phosphorus and fluorine
(d) magnesium and chlorine
3.2
Identify the following combinations of elements in a compound as ionic or molecular.
(a) nitrogen and chlorine
(b) sulfur and oxygen
(c) calcium and chlorine
(d) sodium and nitrogen
3.3
(a)
PCl5
(b)
LiF
Determine if the following formulas represent ionic or molecular compounds.
(c) BaCl2
(d) N2O5
3.4
Determine if the following formulas represent ionic or molecular compounds.
(a)
Al2S3 (c) MgBr2
(b)
P2O5 (d) K2O

3.13 Based on their positions in the periodic table, predict the charge, write the formula, and name the monatomic ions of the following elements.
(c) calcium (b) nitrogen (c) sulfur
Based on their positions in the periodic table, predict the charge, write the formula, and name the monatomic ions of the following elements.
(d) aluminum (b) barium (c) phosphorus
3.18 Name the following polyatomic ions.
SO
3
2- CN ClO
2
-
3.19 Write formulas for the following ions.
(a) nitride (b) nitrate (c) nitrite

3.39
Name the following ionic compounds.
(a)
MgCl2
(b)
Al2O3
(c)
Na2S
(d) KBr
(e) NaNO3
(f) NaClO4
3.40
Name the following ionic compounds.
(a)
BaCl2 (d) KNO2
(b) (NH
4
)
2
S (e) Mg
3
(PO
4
)
2
3.41
(c)
MgO (f) KClO2
For which of the following compounds must we specify the charge on the metal when we name the compound: MgSO4, MnSO4,
CaCl2, CoCl2, AgNO3?

3.42
For which of the following compounds must we specify the charge on the metal when we name the compound: Cr(NO3)2, Ba(NO3)2,
AlBr3, NiS, ZnCl2?
3.43
Given the following formulas, what is the charge on the metal? What is the name of each compound?
(a)CoCl
2
(c) Cr(NO
3
)
3
(b)PbO
2
(d) Fe
2
(SO
4
)
3
3.44
Given the following formulas, what is the charge on the metal? What is the name of each compound?
(a)
CoBr3 (c) Cr2O3
(b)CuCl
2
(d) FeSO
4

3.45
3.46
Write formulas for the following ionic compounds.
(a) cobalt(II) chloride
(b) manganese(II) nitrate
(c) chromium(III) oxide
(d) copper(II) phosphate
Write formulas for the following ionic compounds.
(a) copper(II) bromide
(b) iron(III) nitrate
(c) chromium(VI) oxide
(d) copper(II) chlorate

3.60
Name the following compounds.
(a)
PF5 (c) CO
3.61
(b)PF
3
(d) SO
2
Name the following compounds.
(a)
SO3
(b)
N2O4
(c) NO2
(d) CS2

Name the following compounds or ions. Identify each compound as molecular or ionic.
(a)
NO
3
(b)
NO
3
(c)
KNO
3
(d)
Na
3
N
(e) AlCl
3
(f) PCl
3
(g) TiO
(h) MgO
3.90 Explain why the formula given for each compound is incorrect. calcium hydroxide, CaOH
2 aluminum chloride, AlCl
2 dinitrogen trioxide, N
3
O
2 potassium phosphide, K
3
PO
4