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Principles of Chemistry: A Molecular Approach, 1st Ed.
Nivaldo Tro
Chapter 1
Matter,
Measurement,
and Problem
Solving
g
Roy Kennedy
Massachusetts Bay Community College
Wellesley Hills, MA
Edited by Karen Hattenhauer
Tro, Principles of Chemistry: A Molecular Approach
Consider the statement: “When iron rusts in a closed
container, the mass of the container and its contents
does not change.”
Classify this statement as one of the following.
a) This statement is a theory. (Recall: A theory
attempts to explain why.)
b) This statement is a hypothesis. (Recall: A
hypothesis is a potential explanation for a single
or small number of observations.)
observations )
c) This statement is an observation.
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Consider the statement: “If elements are listed in
order of increasing mass of their atoms, their
chemical reactivity follows a repeating pattern.”
Classify this statement as one of the following.
a) This statement is a theory. (Recall: A theory
attempts to explain why.)
b) This statement is a law. (Recall: A law
summarizes many observations and explain
future behavior.)
behavior )
c) This statement is an hypothesis. (Recall: A
hypothesis is a potential explanation for a single
or small number of observations.)
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Which one of the following would be classified as a
heterogeneous mixture?
a)
b)
c)
d)
Salt water
Brass
Air
Coke
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Sodium Chloride (NaCl) is:
a)
b)
c)
d)
A heterogeneous mixture
A compound
An element
An atom
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Pure Seawater is:
a)
b)
c)
d)
A heterogeneous mixture
A compound
An element
An homogeneous mixture
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Properties of Matter
Question:
Several properties of ozone are listed below. Which are
physical and which are chemical?
a)
b)
c)
d))
e)
Bluish color - physical property
Pungent odor - physical property
Very reactive - chemical property
Decomposes
p
on exposure
p
to ultraviolet light
g - chemical
property
Gas at room temperature - physical property
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Properties of Matter
Question:
Classify each of the following changes as chemical or
physical.
physical
a) Sugar burns when heated on a skillet - chemical change
b) Sugar dissolves in water - physical change
c) Platinum ring becomes dull because of continued
d)
abrasion - physical change
Silver surface becomes tarnished after exposure to air for
a long period of time - chemical change
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Properties of Matter
Question:
Identify any chemical or physical properties and chemical or
physical changes as described in the following description of
iodine.
“ Iodine is a solid having somewhat lustrous, blue-black
crystals. The crystals vaporize readily to a violet-colored gas.
Iodine combines with many metals. For example, aluminum
combines with iodine to give aluminum iodide.”
Answer:
Chemical property – combines with metals (aluminum)
Physical property – lustrous, solid, blue-black crystals, violetcolored gas
Chemical change – reaction with aluminum (aluminum iodide)
Physical change - vaporize
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Which of the following statements does not describe
a chemical property of oxygen?
a) Iron will rust in the presence of oxygen.
b) Oxygen combines with carbon to form carbon
c)
d)
dioxide gas.
The pressure is caused by collision of oxygen
molecules with the sides of the container.
When coal is burned in oxygen, the process is
called combustion.
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Express the following value in scientific notation:
0.000005407
a)
b)
c)
d)
5.407 x 105
5.407 x 106
5.407 x 10-5
5 407 x 10-66
5.407
0.0 0 0 0 0 5407
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Express the following value in standard notation:
9.234 x 106
a)
b)
c)
d)
0.009234
9234000
923400
0 000009234
0.000009234
9.2 3 4 0 0 0
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What is the difference between a Fahrenheit
degree and a Celsius degree?
a) A Fahrenheit degree is larger by a factor of 9/5.
b) A Celsius degree is larger by a factor of 9/5.
c) A Fahrenheit degree and a Celsius degree are
the same size.
Answer: Looking at the figure in the notes comparing
temperature scales, notice that there are more units
between freezing point and boiling point of water in
the Fahrenheit scale than the Celsius scale. This
suggests that the units are in the Fahrenheit scale is
smaller. Recall the equation
t(oC) = 5oC/9oF x [t(oF) – 32oF].
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Temperature Scales
Question:
Express normal body temperature,
temperature 98
98.60
60oF in K
K.
oC
= (oF – 32) = (98.60oF - 32) = 37.00oC
1.8
1.8
o
o
Note: 1.8( C) = F – 32 or oF = 1.8(oC) + 32
K = oC + 273.15 = 37.00oC + 273.12 = 310.15 K
Note: oC = K - 273.15
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The hottest place on record in North America is
Death Valley in California. It reached a temperature
of 329.9 K in 1913. What is this temperature reading
in degrees Celsius?
a)
b)
c)
d)
56.8oC
603.1oC
92.7oC
134oF
Answer:
oC = K – 273.15 = 329.9 K – 273.15 = 56.75 K
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Convert -40.6oC to degrees Fahrenheit.
a)
b)
c)
d)
232.6oF
9.4oF
-105.1
105 1oF
-41.1oF
Answer:
oF = 1.8(oC) + 32 = 1.8(-40.6oC) + 32 = 41.08oF
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