Transcript You are given an aqueous solution that contains a Co 2

Chemical Composition
Stoichiometry Review
© 2012 Pearson Education, Inc.
6.1
How many moles of Ca are 3.01  1023
atoms of calcium?
a.
b.
c.
d.
e.
3.01 mol
1.81  1047 mol
1.00 mol
0.500 mol
3.01  1023 mol
© 2012 Pearson Education, Inc.
6.3
How many grams are in 1.000 mol of iron?
a.
b.
c.
d.
e.
1.000 g
6.022  1023 g
0.01791 g
26.00 g
55.85 g
© 2012 Pearson Education, Inc.
6.4
What is the molar mass of ammonium
nitrate?
a.
b.
c.
d.
e.
112.12 g/mol
80.05 g/mol
66.04 g/mol
114.00 g/mol
95.23 g/mol
© 2012 Pearson Education, Inc.
6.6
What is the mass of 4.55  1023 copper
atoms?
a.
b.
c.
d.
e.
4.55 g
4.31  1045 g
1.18  10–2 g
6.02  1023 g
48.0 g
© 2012 Pearson Education, Inc.
6.7
How many moles are in 5.672 g of iron(III)
sulfate?
a.
b.
c.
d.
e.
3.730  10–2 mol
2.268  10–3 mol
2.268  103 mol
5.672  10–3 mol
1.418  10–2 mol
© 2012 Pearson Education, Inc.
6.9
How many moles are in 5.6 g of lithium
nitride?
a.
b.
c.
d.
e.
0.27 mol
0.20 mol
0.16 mol
0.56 mol
2.0  102 mol
© 2012 Pearson Education, Inc.
6.11
How many moles of oxygen are in 3.45 mol
of diphosphorus pentoxide?
a.
b.
c.
d.
e.
6.90 mol O
3.45 mol O
5.75 mol O
13.5 mol O
17.3 mol O
© 2012 Pearson Education, Inc.
6.14
What is the mass of 5.660 mol of dinitrogen
tetrahydride?
a.
b.
c.
d.
e.
90.70 g
0.1765 g
5.66 g
181.4 g
0.353 g
© 2012 Pearson Education, Inc.
6.19
An unknown compound has a molar mass of
118.10 g/mol. Given the following mass percent
composition, calculate the empirical and molecular
formulas: 40.7% C, 5.13% H, and 54.2% O.
a.
b.
c.
d.
e.
CH1.5O and C2H3O2
C3H5O3 and C6H10O6
C4H6O4 and C8H12O8
C4H6O4 and C2H3O2
C2H3O2 and C4H6O4
© 2012 Pearson Education, Inc.
6.22
What is the empirical formula of ascorbic
acid, C6H8O6, a compound found in citrus
fruits?
a.
b.
c.
d.
e.
C6H8O6
C4H4O4
C3H4O3
CHO
CH2O
© 2012 Pearson Education, Inc.
6.23
Identify the diatomic molecule that has a
mass of 33.86 g and contains 0.891 moles of
molecules.
a.
b.
c.
d.
e.
H2
N2
O2
F2
Cl2
© 2012 Pearson Education, Inc.
6.24
Calculate the empirical formula of a 5.85 g
sample of an unknown chromium oxide
containing 4.00 g of chromium.
a.
b.
c.
d.
e.
Cr2O7
Cr2O4
CrO
CrO1.5
Cr2O3
© 2012 Pearson Education, Inc.
6.25
What is the empirical formula of a compound
that contains 14.5% hydrogen and 85.5%
carbon by mass?
a.
b.
c.
d.
e.
CH
CH2
C2H
C2H3
CH3
© 2012 Pearson Education, Inc.
6.26
What is the mass percentage of oxygen in
glycerol, C3H8O3?
a.
b.
c.
d.
e.
6.25%
26.08%
54%
52.12%
64.32%
© 2012 Pearson Education, Inc.
6.27
The empirical formula of a compound is
found to be CH2O. If its molar mass is
180.2 g/mol, what is the molecular formula
of the compound?
a.
b.
c.
d.
e.
CH2O
C3H6O3
C6H12O6
C2H4O2
None of the above
© 2012 Pearson Education, Inc.
6.28
A variety of Freon contains 69.58% chlorine
by mass. How many grams of chlorine are
contained in 11.3 g of this substance?
a.
b.
c.
d.
e.
7.86 g
5.35 g
7.863 g
0.1624 g
None of the above
© 2012 Pearson Education, Inc.
6.29
What is the mass percentage of oxygen in
potassium chlorate?
a.
b.
c.
d.
e.
6.527%
13.06%
19.60%
39.17%
None of the above
© 2012 Pearson Education, Inc.
6.30
A compound is found to contain 60.00% C,
4.48% H and 35.53% O. What is its
empirical formula?
a.
b.
c.
d.
e.
C9H8O4
C3H2O
C2H2O2
C2H2O
None of the above
© 2012 Pearson Education, Inc.