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WorksheetsLabChem_Ch1_Ch2_Safety
Total questions: 34
Worksheet time: 17mins
You find an unknown substance that cannot be separated by filtration, evaporation, or distillation. Would the explanation that this substance is an element be scientifically valid?
Yes, because elements cannot be separated by ordinary chemical means.
Yes, because elements are pure substances made of one type of atom.
No, because the substance could be a homogeneous mixture.
No, because the substance could be a compound, which also cannot be separated by physical means.
We know that air is a mixture and not a compound because___.
it can be heated to a higher temperature.
it can be compressed to a smaller volume.
its components are chemically combined
its composition can vary
Technological development of a chemical product often
lags behind basic research on the same substance.
does not involve chance discoveries.
is driven by curiosity.
is done for the sake of learning something new.
The label on a tube of toothpaste tells you it contains "the most whitening power of any toothpaste on the market." What would be the best way for you to start to evaluate this claim?
See if it's repeated anywhere else on the packaging.
Compare the color of the toothpaste with the colors of others on the market.
Research what ingredients actually whiten teeth, and see if the toothpaste contains one of those ingredients.
See if there's a similar brand of toothpaste that claims to have the "second-most whitening power of any toothpaste on the market."
The primary motivation behind basic research is to
develop new products.
make money.
understand an environmental problem.
gain knowledge.
The branch of chemistry that involves the study of substances and processes occurring in living things is called
biochemistry.
organic chemistry.
physical chemistry.
theoretical chemistry.
Using mathematical models and computer models to understand a chemical principle is an example of
biochemistry.
physical chemistry.
analytical chemistry.
theoretical chemistry.
Two chemistry students are investigating the properties of mined quartz (SiO4). They are most likely studying in the field of
biochemistry.
physical chemistry.
organic chemistry.
inorganic chemistry.
Extensive properties
include boiling point.
do not depend on the amount of matter present.
include volume and mass.
all depend on the chemical composition of the matter present.
Which is NOT true about the liquid state of matter?
Liquids have definite volume and definite shape.
Liquids take the shape of their container.
The liquid state has a definite volume and an indefinite shape.
The particle in a liquid can easily move past each other.
Which of the following is an intensive property of matter?
volume
mass
energy content
density
A compound is
a substance that is composed of two or more elements that are chemically bonded.
a molecule formed by atoms of the same element.
another word for an atom.
any substance that can be split apart.
The vertical columns of the periodic table are called
periods.
rows.
groups.
chemicals.
All of the following are steps in the scientific method except
observing and recording data.
forming a hypothesis.
discarding data inconsistent with the hypothesis.
making predictions based on a theory.
Which of these statements about the scientific method is NOT true?
All experiments must follow the same step-by-step procedure.
Experiments may be repeated several times.
Some unexpected results can be beneficial.
Experimental results may or may not support the hypothesis.
An experiment was designed to measure the effect of sulfur dioxide emissions from a power plant on the pH of rain falling downwind of the plant. In this experiment, the average pH of rainwater upwind from the plant would be considered (NB: sulfur dioxide is a major contributor to air pollution and leads to acid rain)
a model.
a variable.
the hypothesis.
the control.
A theory is accepted as the explanation of an observed phenomenon until
one study contradicts the theory.
repeated observations conflict with the theory.
a new method is used to gather data.
a leading scientist feels that it is invalid.
The unit m3 is used to express
length.
mass.
volume.
density.
SI base units for time and mass are
hour and gram
minutes and kilogram
seconds and kilogram
minutes and gram
One cubic centimeter is equivalent to
1 milliliter.
1 gram.
1 liter.
1 kilogram.
The number of significant figures in the measurement 0.000305 kg is
two.
three.
six.
seven.
What is the sum of 100.0g and 0.01g, expressed in scientific notation and written with the correct number of significant figures?
10001 x 102 g
1.0 x 102 g
1.000 x 102 g
1.00 x 102 g
Always return all unused chemicals to their original containers.
True
False
The proper way to dispose of liquids is
down the drain
as instructed by the teacher
out the window
put them back in the container you got them from
Horseplay or practical jokes in the laboratory are
always against the rules.
okay.
not dangerous.
okay if you are working alone.
Hot glass looks the same as cold glass.
True
False
If a piece of equipment is not working properly, stop, turn it off, and tell
the custodian.
your lab partner.
your best friend in the class.
the science instructor.
Approved eye protection devices (goggles) are worn in the laboratory
to avoid eye strain.
to improve your vision.
only if you don't have corrective glasses.
any time chemicals, heat, or glassware are used.
All chemicals in the lab are to be considered dangerous.
True
False
In a laboratory, which of the following should not be worn?
loose clothing.
dangling jewelry.
sandals.
all of the above
Never remove chemicals or other equipment from the laboratory.
True
False
Flammable materials, like alcohol, should never be dispensed or used near
an open door.
an open flame.
another student.
a sink.
Chipped or cracked glassware is okay to use in the laboratory.
True
False
Which of the following could be used to prevent inhalation?
Using gloves
Wearing goggles
Wearing aprons
Wafting
