Chemistry Reference
In-Depth Information
2.120
Calculate the density of a cube with each edge 3.93 cm
and mass 171 g.
2.121 Calculate the density of a cube with each edge 0.0393 m
and mass 0.171 kg.
2.122
Compare the sizes, masses, and densities of the cubes
in Problems 2.120 and 2.121.
2.123
Calculate the number of particles of volume
that can fit into a cubic box of edge length
2.136
Calculate the number of
(a) Millimeters in
1.21
10
3
m
5.09
10
6
m
3
(b) Milliliters in
(c) Milligrams in kg
2.137 Calculate the results of the following calculations to the
proper number of significant digits:
(a)
(b)
(c)
2.138
A certain brand of vitamin pill contains g of the
vitamin per pill; another brand has 0.3460 mg of the vi-
tamin per pill. Which is the better buy, all other factors
being equal?
2.139
A nurse who is directed to give a patient a pill that has
0.150 cg of active ingredients has no pills with centi-
grams as units. What pill labeled in milligrams should
the nurse administer?
2.140 Under a certain set of conditions, the density of water is
1.00 g/mL and that of oxygen gas is 1.30 g/L. Which
will float on the other?
2.141 Calculate the number of liters in
(a) 62.1 mL (b)
(c) (d)
2.142
Calculate the sum of cm
7.09
10
6
mm.
2.143
Calculate the result of the following calculation:
3.12
10
3
2.0
(9.99
10
7
mg)
(3.36
10
3
g)
10
22
cm
3
(2.49
10
3
kg)/(7.31
10
1
cm)
3
1.00 m.
2.124
Calculate the density in grams per milliliter of a cubic
unit cell (see Example 2.34) of edge
(50.334 g
49.01 g)/ (39.11 cm
3
)
6.63
10
8
cm
346.0
5.09
10
25
and mass kg.
2.125 Calculate the mass of one unit cell (see Example 2.34)
of a substance with density 2.50 g/mL if its cubic unit
cell has an edge m.
2.126 A unit cell of a substance has a mass of
9.10
10
10
1.98
10
22
g.
One particle of the substance has a mass of
How many particles are in each unit cell?
2.127
Calculate the number of cubic centimeters in a rectan-
gular box
4.94
10
23
g.
1.21
10
1
m by 12.2 cm by 6.01
10
2
mm
2.128 Calculate the density in grams per milliliter of an object
with a volume of 0.6912 L and a mass of 460.7 g.
2.129
How many
0.0293 m
3
703 cm
3
2.28
10
5
mm
3
3.44
10
28
m
3
particles will fit into a
1.71
10
8
4.00-mL vessel?
2.130
Explain how it is possible to calculate an answer having
five significant digits using two measurements having
two significant digits each and two having four signifi-
cant digits each.
2.131 A certain atom is spherical with radius
2.103
10
22
g
6.18
10
23
g
2.11
10
9
cm
8.10
10
12
cm
2
2.144 Convert the density of air in a portion of the upper
atmosphere, to grams per milliliter.
2.145
Calculate the sum of 2.00 m and 0.200 mm. Attempt to
draw a picture of this sum to the proper scale. Explain
the effect in terms of significant digits.
2.146
Calculate the density of a 25.0% by mass sodium chlo-
ride solution in water if 253 g of sodium chloride is
used to make 850 mL of the solution.
2.147
Explain why a football referee, after two successive
defensive offside penalties on a first down, rules
without a measurement
that a new first down has been
achieved, but does not do so after a first-down
running play for no gain followed by two offside
penalties.
2.148 The density of a solution 25.0% by mass sodium chlo-
ride (table salt) in water is 1.19 g/mL. Calculate the
mass of sodium chloride in 842 mL of the solution.
2.149
Calculate the approximate height in meters of the
man in the cubic meter box (Figure 2.7). Use a ratio
2.2
10
10
m,
10
4
kg/m
3
,
7.3
10
23
2.78
and its mass is g. Calculate its density.
2.132 Perform the following calculations, and report the re-
sults to the proper number of significant digits:
(a) (6.53 cm)(7.113 cm)(1.9 cm)
(b)
(c)
2.133
Using the densities in Table 2.5, identify the metal in a
cube with 3.00-cm edges and a mass of 579 g.
2.134 A certain road map of Maine shows part of Canada. The
distances in Canada are shown in kilometers, and the
legend states: “To convert kilometers to miles, multiply
by 0.62.” What is actually being converted?
2.135 Calculate the results of the following calculations to the
proper number of significant digits:
(a)
(7.19 kg)/ [ (6.12
10
2
cm) (25.7 cm) (3.3 cm) ]
(6.9021 g
0.016 g)/ (5.1274 cm
3
)
1.36
10
24
g
6.17
10
23
g
1.36
10
24
g
6.17
10
23
g
4.05
10
9
cm
4.11
10
8
cm
2
(b)
