Measurement - Fundamentals of Chemistry - page 74

of the height of the man to the height of the box in the
figure, which is equal to the ratio of the heights in real
life.
(a) Use a metric ruler to measure the figure.
(b) Use an inch ruler.
(c) State another reason why the metric system is eas-
ier to use than the English system of measurement.
2.150 Repeat Problem 2.149 but estimate the man's width at
his waist instead of his height.
2.151 Calculate the value of “72.90 ks” in (a) minutes and
(b) hours.
2.152 If a patient has a blood count of 835 white corpuscles
per cubic millimeter, what is the number of white cor-
puscles per milliliter?
2.153 (a) Draw a figure showing the addition of the lengths
of two line segments, 20.0 cm and 0.20 cm.
(b) Can you do the same with 20.0 cm and 0.0020 cm?
Explain.
2.154 How many grains of sand, each with a volume of
1.0 mm 3 , could be held in a volume approximately
equal to that of the Earth? (The Earth's radius is 6.4
10 3 km. For a sphere, )
2.155 (a) A bank usually charges 16.0% interest for a certain
type of loan. If the bank advertises a special 15.0%
discount for that type of loan, what is the actual rate?
(b) The percentage of a certain ore in the rock from a
mine is 19%. The percentage of iron in the ore is
69%. What is the percentage of iron in the rock?
2.156 Calculate the length in meters of each side of a cube
that has a volume of
2.157 Calculate the radius of a sphere of volume
2.158 Equal volumes of water (density 1.00 g/mL) and ethyl
alcohol (density 0.789 g/mL) are combined. If the total
volume is 190% of the volume of each component,
what is the density of the solution?
2.159 Calculate the length of each side of a cube that has a
volume of (Be sure to use the proper units
and the proper number of significant digits.)
2.160 Calculate the temperature in kelvins of each of the fol-
lowing:
(a) (b)
(c) (d)
2.161 Calculate the mass of gold in a bracelet that contains
66.7% gold by mass and that has a volume of 17.9 mL
and a density of 14.9 g/mL.
2.162 How many significant digits are in the value ? (The
zero is not left of all other digits, right of all other dig-
its, or between all other digits.) How many are there in
its Celsius equivalent?

2.163 Calculate the depth of water in centimeters in a cubic
box (not full) with 40.0-cm edges if the mass of the
contents is 25.6 kg.
2.164 Calculate the length of a rectangular solid if its density
is its mass is 512 g, its width is 9.12 cm,
and its thickness is 0.250 cm.
2.165 A vitamin pill maker produces pills with a mass of 1.00
g each. If each of the following indicates the mass of
active ingredient, what percentage of the pill is active in
each case?
(a) 3.00 mg (b) 0.300 mg (c) 300 mg
2.166 What is the volume of a cube whose edge measures:
(a) 4.99 cm (b) cm
2.167 Using the densities in Table 2.5, identify the substance
in a sphere with a 3.00-cm radius and a mass of 177 g.

6.12 g/cm 3 ,

6.13 10 8

4

3 r 3 )

( V

2.168 Calculate the average density of the Earth, assuming it
to be spherical with radius 6400 km and mass 6.1
10 24 kg.
2.169 Calculate the temperature in degrees Fahrenheit of each
of the following:
(a) 250 K (b) 0 K (c) 273 K (d) 329 K
2.170 Which of the following amounts of money would more
likely be rounded by a merchant to the nearest $10?
(a) $1303.22 or (b) $13.22
2.171 (a) Calculate the price of an average grain of a certain
type of rice if a pound of this rice costs $2.12 and
there are grains of rice per pound.
(b) How many significant digits should be reported in
this calculation?
2.172 Calculate the mass of a sphere of radius 2.75 cm and
density 0.382 g/cm 3 .
2.173 Calculate the density of a sphere of radius 5.12 cm and
mass 441 g. )
2.174 Calculate the density in grams per cubic centimeter
of an average chlorine atom, which has a radius
of

4

3 r 3 )

( V

4

3 r 3

V

4.1 10 4

6.92 10 7 cm 3 .

9.02 cm 3 .

4

3 r 3 )

( V

4

3 r 3

( V

74.3 cm 3 .

1.05 10 10 5.89 10 23

m and a mass of g.

4

3 r 3 )

( V

2.175 Equal volumes of water (density 1.00 g/mL) and
ethyl alcohol (density 0.789 g/mL) are combined. If the
density of the resulting solution is 0.942 g/mL, what
is the volume of the solution compared to that of the
water?
2.176 Calculate the volume of a (spherical) atom of chlorine,
which has a radius of m. )
2.177 Calculate the temperature in Celsius of each of the fol-
lowing: (a) (b) and (c) How many
significant digits should be reported for each?

98.6°F 40°F

37°F 212°F

1.05 10 10

4

3 r 3

( V

0°F

19°F, 19.0°F, 0.0°F.