CHEM121 MIDTERM EXAM
EXPECTED QUESTIONS AND CORRECT
ANSWERS
An object with a mass of 0.255 kg and density of 2.89
g/cm3 measures 34 mm in length and 46 mm in width.
What is the height of the object?
5.6 cm
A 0.150 kg metallic block measures 25.0 mm in length,
43.0 mm in width, and 19 .0 mm in height. What is the
density of the metallic block in g/cm3?
7.34 g/cm3
How would you determine the density of an irregular
object?
D = m/v, so measure the mass of the object using a
balance. Then to find volume, fill a graduated cylinder with
a known amount of water and immerse the object in the
water. The amount of displaced water is the volume in
cm3 or mL
What is the base unit for length in the metric system?
m
What is the base unit for mass in the metric system?
kg
What is the base unit for volume in the metric system?
L
It is important that scientists use units that are
understood on a global level. These units are referred
to as SI units which stands for _____
, international system of units
An experimental mouse weighs about 4.41 x 10-2 lbs.
What would the weight be in the SI unit for mass?
0.0200 kg*
Accuracy is defined as how close a measured value
comes to a _____.
true value
Precision is defined as how _____ the measured
values are to one another.
reproducible
Structural isomers are considered molecules with the
same ____________.
kinds and number of atoms but a different arrangement of
these atoms
Which of the following is not a correct element name-
symbol combination?
arsenic, Ar
Isotopes of carbon differ with respect to the number of
_________.
neutrons
Elements in group 17 are considered _____________.
halogens
Due to periodicity, which of the following elements
has chemical behavior similar to that of Oxygen?
sulfur
Where would you expect to find a stored bottle of HCl
in the laboratory?
in the storage cabinet labeled strong acids
Where would you expect to find a stored bottle of
NaOH in the laboratory?
in the storage cabinet labeled strong bases
EXPECTED QUESTIONS AND CORRECT
ANSWERS
An object with a mass of 0.255 kg and density of 2.89
g/cm3 measures 34 mm in length and 46 mm in width.
What is the height of the object?
5.6 cm
A 0.150 kg metallic block measures 25.0 mm in length,
43.0 mm in width, and 19 .0 mm in height. What is the
density of the metallic block in g/cm3?
7.34 g/cm3
How would you determine the density of an irregular
object?
D = m/v, so measure the mass of the object using a
balance. Then to find volume, fill a graduated cylinder with
a known amount of water and immerse the object in the
water. The amount of displaced water is the volume in
cm3 or mL
What is the base unit for length in the metric system?
m
What is the base unit for mass in the metric system?
kg
What is the base unit for volume in the metric system?
L
It is important that scientists use units that are
understood on a global level. These units are referred
to as SI units which stands for _____
, international system of units
An experimental mouse weighs about 4.41 x 10-2 lbs.
What would the weight be in the SI unit for mass?
0.0200 kg*
Accuracy is defined as how close a measured value
comes to a _____.
true value
Precision is defined as how _____ the measured
values are to one another.
reproducible
Structural isomers are considered molecules with the
same ____________.
kinds and number of atoms but a different arrangement of
these atoms
Which of the following is not a correct element name-
symbol combination?
arsenic, Ar
Isotopes of carbon differ with respect to the number of
_________.
neutrons
Elements in group 17 are considered _____________.
halogens
Due to periodicity, which of the following elements
has chemical behavior similar to that of Oxygen?
sulfur
Where would you expect to find a stored bottle of HCl
in the laboratory?
in the storage cabinet labeled strong acids
Where would you expect to find a stored bottle of
NaOH in the laboratory?
in the storage cabinet labeled strong bases
