OpenStax Chemistry: Atoms First 2e
3.7: Molecular and Ionic Compounds
Chemistry: Atoms First 2e
3: Electronic Structure and Periodic Properties of Elements
3.7: Molecular and Ionic Compounds
95. Using the periodic table, predict whether the following chlorides are ionic or covalent: KCl,
NCl3, ICl, MgCl2, PCl5, and CCl4.
Solution
In general, those elements that are widely separated in the periodic table—that is, at the extreme
left and extreme right—will form compounds that are ionic. Those elements that are near one
another in the periodic table generally will form covalent compounds. More specifically, when a
metal is combined with one or more nonmetals, the compound is usually ionic. Covalent
compounds are usually formed by a combination of nonmetals. Ionic: KCl, MgCl2; Covalent:
NCl3, ICl, PCl5, CCl4
96. Using the periodic table, predict whether the following chlorides are ionic or covalent: SiCl4,
PCl3, CaCl2, CsCl, CuCl2, and CrCl3.
Solution
Covalent compounds are usually formed by a combination of nonmetals. Ionic compounds are
usually formed when a metal is combined with one or more nonmetals. Ionic: CaCl2, CsCl,
CuCl2; Covalent: SiCl4, PCI3
97. For each of the following compounds, state whether it is ionic or covalent. If it is ionic, write
the symbols for the ions involved:
(a) NF3
(b) BaO
(c) (NH4)2CO3
(d) Sr(H2PO4)2
(e) IBr
(f) Na2O
Solution
(a) covalent; (b) ionic, Ba2+, O2–; (c) ionic, , ; (d) ionic, Sr2+, ; (e) covalent; (f)
ionic, Na , O
+ 2–
98. For each of the following compounds, state whether it is ionic or covalent, and if it is ionic,
write the symbols for the ions involved:
(a) KClO4
(b) Mg(C2H3O2)2
(c) H2S
(d) Ag2S
(e) N2Cl4
(f) Co(NO3)2
Solution
(a) ionic, K+, ; (b) ionic, Mg2+, C2H3O2, charge 2–; (c) covalent; (d) ionic, Ag+, S2–; (e)
covalent; (f) ionic, Co2+,
99. For each of the following pairs of ions, write the symbol for the formula of the compound
they will form:
(a) Ca2+, S2–
(b) ,
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3.7: Molecular and Ionic Compounds
Chemistry: Atoms First 2e
3: Electronic Structure and Periodic Properties of Elements
3.7: Molecular and Ionic Compounds
95. Using the periodic table, predict whether the following chlorides are ionic or covalent: KCl,
NCl3, ICl, MgCl2, PCl5, and CCl4.
Solution
In general, those elements that are widely separated in the periodic table—that is, at the extreme
left and extreme right—will form compounds that are ionic. Those elements that are near one
another in the periodic table generally will form covalent compounds. More specifically, when a
metal is combined with one or more nonmetals, the compound is usually ionic. Covalent
compounds are usually formed by a combination of nonmetals. Ionic: KCl, MgCl2; Covalent:
NCl3, ICl, PCl5, CCl4
96. Using the periodic table, predict whether the following chlorides are ionic or covalent: SiCl4,
PCl3, CaCl2, CsCl, CuCl2, and CrCl3.
Solution
Covalent compounds are usually formed by a combination of nonmetals. Ionic compounds are
usually formed when a metal is combined with one or more nonmetals. Ionic: CaCl2, CsCl,
CuCl2; Covalent: SiCl4, PCI3
97. For each of the following compounds, state whether it is ionic or covalent. If it is ionic, write
the symbols for the ions involved:
(a) NF3
(b) BaO
(c) (NH4)2CO3
(d) Sr(H2PO4)2
(e) IBr
(f) Na2O
Solution
(a) covalent; (b) ionic, Ba2+, O2–; (c) ionic, , ; (d) ionic, Sr2+, ; (e) covalent; (f)
ionic, Na , O
+ 2–
98. For each of the following compounds, state whether it is ionic or covalent, and if it is ionic,
write the symbols for the ions involved:
(a) KClO4
(b) Mg(C2H3O2)2
(c) H2S
(d) Ag2S
(e) N2Cl4
(f) Co(NO3)2
Solution
(a) ionic, K+, ; (b) ionic, Mg2+, C2H3O2, charge 2–; (c) covalent; (d) ionic, Ag+, S2–; (e)
covalent; (f) ionic, Co2+,
99. For each of the following pairs of ions, write the symbol for the formula of the compound
they will form:
(a) Ca2+, S2–
(b) ,
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