Chapter 19:
Chemical Bonds
Practice Test
1.
The overall charge on the polyatomic dichromate ion, Cr
2
O
7
2-
, is 2-. What is the oxidation number of chromium in this polyatomic ion?
a.
+7
b.
+2
c.
+4
d.
+6
Hint
2.
Sulfuric acid has the formula H
2
SO
4
. Sulfur makes up what percentage of the mass of a sulfuric acid molecule?
a.
33.3%
b.
14.3%
c.
32.6%
d.
48.5%
Hint
3.
The overall charge on the polyatomic phosphate ion, PO
4
3-
, is 3-. What is the oxidation number of phosphorus in the phosphate ion?
a.
+4
b.
+8
c.
+5
d.
+1
Hint
4.
What is the formula for iron(III) oxide?
a.
Fe
3
O
2
b.
Fe
2
O
3
c.
FeO
d.
FeO
2
Hint
5.
What is the formula of the compound formed when ammonium ions, NH
4
+
, and sulfate ions, SO
4
2-
, combine?
a.
(NH
4
)
2
SO
4
b.
(NH
4
)
2
(SO
4
)
2
c.
NH
4
(SO
4
)
2
d.
NH
4
SO
4
Hint
6.
What is the formula for carbon tetrachloride?
a.
C
4
Cl
b.
C
2
Cl
2
c.
CCl
d.
CCl
4
Hint
7.
What is the formula for potassium chlorate?
a.
K(ClO
3
)
2
b.
KClO
3
c.
K
2
ClO
3
d.
K
2
(ClO
3
)
2
Hint
8.
What is the formula for lead(IV) oxide?
a.
PbO
4
b.
Pb
4
O
c.
PbO
2
d.
Pb
2
O
Hint
9.
Show that the sum of positive and negative charges in a unit of calcium chloride (CaCl
2
) equals zero.
a.
-1 + 1 = 0
b.
-3 + 3 = 0
c.
-2 + 2 = 0
d.
0 + 0 = 0
Hint
10.
How many hydrogen atoms are in three molecules of ammonium phosphate, (NH
4
)
3
PO
4
?
a.
12
b.
4
c.
9
d.
36
Hint
