CHEM 104 MODULE 1 – QUESTIONS AND
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1. A student is asked to identify the branch of chemistry primarily concerned
with the composition, structure, properties, and changes of matter. Which
answer is correct?
A. Biology
B. Physics
C. Chemistry
D. Geology
: Chemistry is the scientific study of matter, including its composition, properties,
structure, and the changes it undergoes. Biology studies living organisms,
physics focuses on energy and forces, and geology studies Earth materials and
processes.
2. During a laboratory exercise, a student records the mass of a sample as
15.23 g using a digital balance. Which characteristic of scientific measurement
does this demonstrate?
A. Observation only
B. Precision in measurement
C. Scientific theory
D. Scientific law
: Recording measurements to the appropriate number of decimal places
demonstrates precision and proper use of laboratory equipment. Scientific
theories and laws explain natural phenomena rather than describe
measurements.
,3. Which statement best distinguishes a physical property from a chemical
property?
A. A physical property is observed without changing a substance's identity.
B. A chemical property can always be measured without experimentation.
C. Physical properties exist only for solids.
D. Chemical properties are visible without reactions.
: Physical properties such as density, color, and melting point can be observed
without altering chemical composition. Chemical properties describe how
substances react to form new substances.
4. Which of the following represents a chemical change?
A. Ice melting
B. Water boiling
C. Iron rusting
D. Glass breaking
: Rusting produces iron oxide, a new substance, making it a chemical change.
Melting, boiling, and breaking involve only physical changes without altering
chemical identity.
5. A laboratory technician observes a colorless liquid with a boiling point of
100°C at standard atmospheric pressure. This observation describes which
type of property?
A. Chemical property
B. Intensive physical property
C. Extensive property
D. Nuclear property
: Boiling point is an intensive physical property because it does not depend on
the amount of substance present.
,6. A researcher heats a pure sample of water until it changes from a liquid to
a gas. What type of change has occurred?
A. Chemical change
B. Nuclear change
C. Physical change
D. Oxidation reaction
: A phase change from liquid to gas does not alter the chemical composition of
water (H₂O). The substance remains water, making this a physical change rather
than a chemical or nuclear process.
7. Which of the following is classified as a homogeneous mixture?
A. Granite
B. Salad
C. Saltwater
D. Sand and iron filings
: Saltwater has a uniform composition throughout, making it a homogeneous
mixture. Granite, salad, and sand mixed with iron filings have visibly different
components and are heterogeneous mixtures.
8. A chemist separates ethanol from water using differences in boiling points.
Which separation technique is most appropriate?
A. Filtration
B. Distillation
C. Decantation
D. Centrifugation
: Distillation separates liquids based on differences in their boiling points.
Filtration separates solids from liquids, while decantation and centrifugation are
not appropriate for separating completely miscible liquids like ethanol and water.
, 9. Which statement accurately describes an element?
A. It consists of two or more chemically combined elements.
B. It can be separated into simpler substances by physical means.
C. It contains only one type of atom.
D. It is always found in nature as a compound.
: An element is a pure substance composed of only one kind of atom.
Compounds contain two or more different elements chemically bonded together,
while mixtures can be separated by physical methods.
10. Which laboratory practice best promotes safety when handling unknown
chemicals?
A. Smell the chemical directly to identify it.
B. Taste a small amount to determine its composition.
C. Read the label and Safety Data Sheet (SDS) before handling.
D. Mix it with another chemical to observe its reaction.
: Reviewing the container label and Safety Data Sheet before handling an
unknown chemical is a fundamental laboratory safety practice. Directly
smelling, tasting, or mixing unknown chemicals can expose individuals to
significant hazards.
11. A sample has a mass of 48.0 g and occupies a volume of 16.0 mL. What is
its density?
A. 0.33 g/mL
B. 3.0 g/mL
C. 16.0 g/mL
D. 64.0 g/mL
: Density is calculated using the formula Density = Mass ÷ Volume. Therefore,
48.0 g ÷ 16.0 mL = 3.0 g/mL. The other options result from incorrect
calculations or misuse of the formula.
12. Which SI base unit is used to measure the amount of substance?
ANSWERS | VERIFIED AND WELL DETAILED
ANSWERS PLUS S | GUARANTEED PASS |
LATEST EXAM UPDATE | EXAM PREP | STUDY
GUIDE | PRACTICE TEST | DOWNLOAD
INSTANT PDF
1. A student is asked to identify the branch of chemistry primarily concerned
with the composition, structure, properties, and changes of matter. Which
answer is correct?
A. Biology
B. Physics
C. Chemistry
D. Geology
: Chemistry is the scientific study of matter, including its composition, properties,
structure, and the changes it undergoes. Biology studies living organisms,
physics focuses on energy and forces, and geology studies Earth materials and
processes.
2. During a laboratory exercise, a student records the mass of a sample as
15.23 g using a digital balance. Which characteristic of scientific measurement
does this demonstrate?
A. Observation only
B. Precision in measurement
C. Scientific theory
D. Scientific law
: Recording measurements to the appropriate number of decimal places
demonstrates precision and proper use of laboratory equipment. Scientific
theories and laws explain natural phenomena rather than describe
measurements.
,3. Which statement best distinguishes a physical property from a chemical
property?
A. A physical property is observed without changing a substance's identity.
B. A chemical property can always be measured without experimentation.
C. Physical properties exist only for solids.
D. Chemical properties are visible without reactions.
: Physical properties such as density, color, and melting point can be observed
without altering chemical composition. Chemical properties describe how
substances react to form new substances.
4. Which of the following represents a chemical change?
A. Ice melting
B. Water boiling
C. Iron rusting
D. Glass breaking
: Rusting produces iron oxide, a new substance, making it a chemical change.
Melting, boiling, and breaking involve only physical changes without altering
chemical identity.
5. A laboratory technician observes a colorless liquid with a boiling point of
100°C at standard atmospheric pressure. This observation describes which
type of property?
A. Chemical property
B. Intensive physical property
C. Extensive property
D. Nuclear property
: Boiling point is an intensive physical property because it does not depend on
the amount of substance present.
,6. A researcher heats a pure sample of water until it changes from a liquid to
a gas. What type of change has occurred?
A. Chemical change
B. Nuclear change
C. Physical change
D. Oxidation reaction
: A phase change from liquid to gas does not alter the chemical composition of
water (H₂O). The substance remains water, making this a physical change rather
than a chemical or nuclear process.
7. Which of the following is classified as a homogeneous mixture?
A. Granite
B. Salad
C. Saltwater
D. Sand and iron filings
: Saltwater has a uniform composition throughout, making it a homogeneous
mixture. Granite, salad, and sand mixed with iron filings have visibly different
components and are heterogeneous mixtures.
8. A chemist separates ethanol from water using differences in boiling points.
Which separation technique is most appropriate?
A. Filtration
B. Distillation
C. Decantation
D. Centrifugation
: Distillation separates liquids based on differences in their boiling points.
Filtration separates solids from liquids, while decantation and centrifugation are
not appropriate for separating completely miscible liquids like ethanol and water.
, 9. Which statement accurately describes an element?
A. It consists of two or more chemically combined elements.
B. It can be separated into simpler substances by physical means.
C. It contains only one type of atom.
D. It is always found in nature as a compound.
: An element is a pure substance composed of only one kind of atom.
Compounds contain two or more different elements chemically bonded together,
while mixtures can be separated by physical methods.
10. Which laboratory practice best promotes safety when handling unknown
chemicals?
A. Smell the chemical directly to identify it.
B. Taste a small amount to determine its composition.
C. Read the label and Safety Data Sheet (SDS) before handling.
D. Mix it with another chemical to observe its reaction.
: Reviewing the container label and Safety Data Sheet before handling an
unknown chemical is a fundamental laboratory safety practice. Directly
smelling, tasting, or mixing unknown chemicals can expose individuals to
significant hazards.
11. A sample has a mass of 48.0 g and occupies a volume of 16.0 mL. What is
its density?
A. 0.33 g/mL
B. 3.0 g/mL
C. 16.0 g/mL
D. 64.0 g/mL
: Density is calculated using the formula Density = Mass ÷ Volume. Therefore,
48.0 g ÷ 16.0 mL = 3.0 g/mL. The other options result from incorrect
calculations or misuse of the formula.
12. Which SI base unit is used to measure the amount of substance?
