OBJ 4 (Chemistry)
Question 1
• Upon entering your lab station, you realize
you have more chemicals than you need in
order to complete your assignment. What
should you do?
Question 1
• Upon entering your lab station, you realize
you have more chemicals than you need in
order to complete your assignment. What
should you do?
• Use the proper amount of chemicals called
for and return any unused chemicals to the
teacher.
Question 2
• You are instructed to find the density of a
small, irregularly shaped item. Which set of
equipment is best for completing this
assignment?
Question 2
• You are instructed to find the density of a
small, irregularly shaped item. Which set of
equipment is best for completing this
assignment?
• a graduated cylinder and triple beam balance
Question 3
• How much water is in the graduated cylinder?
Question 3
• How much water is in the graduated cylinder?
40.7 ml
Question 4
• What is the charge, location, and relative size
of a proton?
Question 4
• What is the charge, location, and relative size
of a proton?
• Positive (+), in the nucleus, and about the size
of a neutron.
Question 5
• The above graph shows the data collected
when a solid was melted. At which point on
the graph had the solid turned into a liquid?
Question 5
• The above graph shows the data collected
when a solid was melted. At which point on
the graph had the solid turned into a liquid?
• C
Question 6
• During a laboratory experiment, two
substances are combined in a dish. At the end
of the experiment, you use filtration to
retrieve both original substances. What was
made?
Question 6
• During a laboratory experiment, two
substances are combined in a dish. At the end
of the experiment, you use filtration to
retrieve both original substances. Determine
the type of product formed when these two
substances were combined?
• MIXTURE
Question 7
• Before he began an experiment, Chris wrote
out the steps to his procedure and recorded
his conclusion. During the experiment, he
noticed an error in the steps, and adjusted
them to get to the conclusion he predicted.
What did he DO WRONG?
Question 7
• Before he began an experiment, Chris wrote
out the steps to his procedure and recorded
his conclusion. During the experiment, he
noticed an error in the steps, and adjusted
them to get to the conclusion he predicted.
What did he DO WRONG?
• No hypothesis…….
Question 8
• You want to buy a heating system for your
backyard pool. However, you want to make
sure that the energy source of this heating
system does not produce any greenhouse
gases. What type of energy system can be
used without any production of greenhouse
gases?
Question 8
• You want to buy a heating system for your
backyard pool. However, you want to make
sure that the energy source of this heating
system does not produce any greenhouse
gases. What type of energy system can be
used without any production of greenhouse
gases?
• SOLAR
Question 9
• Hybrid cars are a combination of research
done on which two common car parts?
Question 9
• Hybrid cars are a combination of research
done on which two common car parts?
• engines and batteries
Question 10
• Agricultural scientists perform a very useful
job by making sure that fertilizers and
pesticides are used within safe levels for
humans and the environment. Which of the
following areas of study would be useful in
determining the levels of these compounds?
Question 10
• Agricultural scientists perform a very useful
job by making sure that fertilizers and
pesticides are used within safe levels for
humans and the environment. Which of the
following areas of study would be useful in
determining the levels of these compounds?
• CHEMISTRY
Question 11
• Alchemists in the early 1100's tried to convert
common metals into gold. They developed
experimental procedures and apparatus to
gain knowledge about the characteristics of
substances. What is the best way to describe
an alchemist in modern terms?
Question 11
• Alchemists in the early 1100's tried to convert
common metals into gold. They developed
experimental procedures and apparatus to
gain knowledge about the characteristics of
substances. What is the best way to describe
an alchemist in modern terms?
• SCIENTIST
Question 12
• Lisa has two rings with the same size and
diameter. One is made of platinum, and the
other is made of gold. What aspect of
platinum makes that ring heavier than the
gold ring?
Question 12
• Lisa has two rings with the same size and
diameter. One is made of platinum, and the
other is made of gold. What aspect of
platinum makes that ring heavier than the
gold ring?
• Platinum is more dense than gold.
Question 13
• Silicon dioxide (SiO2), also called silica, occurs
naturally in many different forms that have
different properties, such as quartz, sand, and
Cristobalite. What is the primary reason for
the difference in properties (hardness,
brittleness, boiling point, etc.) between these
forms?
Question 13
• Silicon dioxide (SiO2), also called silica, occurs
naturally in many different forms that have
different properties, such as quartz, sand, and
Cristobalite. What is the primary reason for
the difference in properties (hardness,
brittleness, boiling point, etc.) between these
forms?
• differences in intermolecular forces
Question 14
• A student was given the following list of
properties of an unknown substance:
Its molecules exhibit properties of its
constituent atoms.
It exists as a gas in its free state.
Its molecules are diatomic.
It is a pure substance.
Which indicates that it is an element?
Question 14
• A student was given the following list of
properties of an unknown substance:
Its molecules exhibit properties of its
constituent atoms.
It exists as a gas in its free state.
Its molecules are diatomic.
It is a pure substance.
Which indicates that it is an element?
Its molecules exhibit properties of its
constituent atoms.
Question 15
• The periodic table divides elements into
groups and periods. Which group or period
contains atoms that are all radioactive?
Question 15
• The periodic table divides elements into
groups and periods. Which group or period
contains atoms that are all radioactive?
• actinides
Question 16
• Which of the following indicates an increase in
the potential energy of molecules in a unit of
matter?
Question 16
• Which of the following indicates an increase in
the potential energy of molecules in a unit of
matter?
• The matter changes from the
solid to the liquid phase.
Question 17
• When an ax is swung, it has kinetic energy.
When the ax connects with a piece of wood,
the kinetic energy causes the movement of
the ax into the wood and the wood splits.
What other type of energy is produced when
the ax connects with the wood?
Question 17
• When an ax is swung, it has kinetic energy.
When the ax connects with a piece of wood,
the kinetic energy causes the movement of
the ax into the wood and the wood splits.
What other type of energy is produced when
the ax connects with the wood?
heat energy
Question 18
• What is the charge, location, and size of
electrons?
Question 18
• What is the charge, location, and size of
electrons?
• Electrons are negative and are located
outside the nucleus……and are the smallest
Question 19
• Carbon has multiple isotopes. Two naturally
occurring isotopes of carbon are Carbon - 14
and Carbon -12. What aspect of Carbon -14
makes it useful for carbon dating?
Question 19
• Carbon has multiple isotopes. Two naturally
occurring isotopes of carbon are Carbon - 14
and Carbon -12. What aspect of Carbon -14
makes it useful for carbon dating?
• It has a long half-life
Question 20
• If the volume of a sample of ideal gas is
doubled at constant temperature, the
pressure of the gas will—
Question 20
• If the volume of a sample of ideal gas is
doubled at constant temperature, the
pressure of the gas will—
• be half the initial pressure.
Question 21
• During an investigation with gases, you blow
up a balloon and tie it off. Your teacher has
you place the balloon in a freezer
overnight. The air pressure inside the freezer
remains constant. What can you predict about
the balloon when you remove it from the
freezer?
Question 21
• During an investigation with gases, you blow
up a balloon and tie it off. Your teacher has
you place the balloon in a freezer
overnight. The air pressure inside the freezer
remains constant. What can you predict about
the balloon when you remove it from the
freezer?
• The volume of the balloon will have
decreased.
Question 22
• When methane (CH4) is formed, one carbon
atom is combined with four hydrogen atoms.
Why are more hydrogen atoms than carbon
atoms needed to form this compound?
Question 22
• When methane (CH4) is formed, one carbon
atom is combined with four hydrogen atoms.
Why are more hydrogen atoms than carbon
atoms needed to form this compound?
• Carbon needs more electrons.
Question 23
• Which of the following is a property
associated with ionic compounds?
Question 23
• Which of the following is a property
associated with ionic compounds?
• An ionic compound is usually composed of a
nonmetal and a metal.
Question 24
• In which of the following substances does the
repulsion between electron pairs cause the
bonds to adjust to keep the valence electron
pairs as far apart as possible in the
arrangement of atoms?
Question 24
• In which of the following substances does the
repulsion between electron pairs cause the
bonds to adjust to keep the valence electron
pairs as far apart as possible in the
arrangement of atoms?
• molecules
Question 25
• Methane (CH4) is a highly flammable natural
gas. What property of this gas causes its
flammability?
Question 25
• Methane (CH4) is a highly flammable natural
gas. What property of this gas causes its
flammability?
• Methane is a hydrocarbon.
Question 26
• Energy is produced in the Sun by a nuclear
fusion reaction in which two hydrogen atoms
combine to form a helium atom. Two
hydrogen atoms can also react to form
hydrogen gas (H2). What best explains why the
fusion reaction involves a great change in
energy but the hydrogen gas reaction involves
only a small change in energy?
Question 26
• Energy is produced in the Sun by a nuclear fusion
reaction in which two hydrogen atoms combine
to form a helium atom. Two hydrogen atoms can
also react to form hydrogen gas (H2). What best
explains why the fusion reaction involves a great
change in energy but the hydrogen gas reaction
involves only a small change in energy?
• The fusion reaction has nuclear forces as the
energy source.
Question 27
• How much of a sample of a radioactive
element will remain after three half-lives?
Question 27
• How much of a sample of a radioactive
element will remain after three half-lives?
• Only 1/8th of the sample will remain
• 1st half life = 50%
• 2nd half-life = 25%
• 3rd half –life = 12.50% = 1/8
Question 28
• The radioisotope technetium-99 is commonly
used in nuclear medicine on human beings. It
has a half life of six hours, and emits gamma
rays that are detected using a camera. What
makes it possible for this radioactive material
to be used internally in a human body?
Question 28
• The radioisotope technetium-99 is commonly
used in nuclear medicine on human beings. It
has a half life of six hours, and emits gamma
rays that are detected using a camera. What
makes it possible for this radioactive material
to be used internally in a human body?
• It has a short half-life.
Question 29
• A worker at a nuclear power plant discovers a
crack in one of the used fuel cell storage
pools. What hazards does this create?
Question 29
• A worker at a nuclear power plant discovers a
crack in one of the used fuel cell storage
pools. What hazards does this create?
• radiation leakages into the soil
Question 30
• What is an element that can oxidize during a
chemical reaction.
Question 30
• What can oxidize during a chemical reaction?
• magnesium
Question 30
• What can oxidize during a chemical reaction?
• magnesium
Question 31
• What is the name of the compound
represented by N2F4?
Question 31
• What is the name of the compound
represented by N2F4?
• dinitrogen tetrafluoride
• di = 2 tetra = 4
Question 32
• What is the molecular formula of
tetraphosphorus decoxide?
Question 32
• What is the molecular formula of
tetraphosphorus decoxide?
• P4O10
•
Tetra = 4
Deca = 10
Question 33
• ___NH3 + ___O2 → ___N2 + ___H2O
If the equation above were balanced with
lowest-whole-number coefficients, the
coefficient for NH3 would be
Question 33
• ___NH3 + ___O2 → ___N2 + ___H2O
If the equation above were balanced with
lowest-whole-number coefficients, the
coefficient for NH3 would be
• 4
Question 33
• ___NH3 + ___O2 → ___N2 + ___H2O
If the equation above were balanced with
lowest-whole-number coefficients, the
coefficient for NH3 would be
Question 34
• Ben is conducting an experiment. Ben places 5
grams of sugar in 100 milliliters of water. Ben
measures how quickly the sugar dissolves. Ben
takes another 5 gram sample of sugar. Ben
grinds the sugar particles into fine granules.
Ben places 5 grams of fine sugar granules into
100 milliliters of water. Ben measures how
quickly the sugar dissolves. What is the
experiment testing?
Question 34
• Ben is conducting an experiment. Ben places 5
grams of sugar in 100 milliliters of water. Ben
measures how quickly the sugar dissolves. Ben
takes another 5 gram sample of sugar. Ben grinds
the sugar particles into fine granules. Ben places
5 grams of fine sugar granules into 100 milliliters
of water. Ben measures how quickly the sugar
dissolves. What is the experiment testing?
• HOW PARTICLE SIZE AFFECTS SOLUBILITY
Question 35
• What will not increase the dissolving rate for a
solvent?
Question 35
• What will not increase the dissolving rate for a
solvent?
• increasing the amount of solute
Question 36
• A specific liquid is known as the universal
solvent, because it is important as a solvent
not only in living organisms but also in the
environment. Identify this liquid.
Question 36
• A specific liquid is known as the universal
solvent, because it is important as a solvent
not only in living organisms but also in the
environment. Identify this liquid.
• water
Question 37
• Rosa needs to make a supersaturated solution
for an experiment. What is the BEST way Rosa
can make a supersaturated solution?
Question 37
• Rosa needs to make a supersaturated solution
for an experiment. What is the BEST way Rosa
can make a supersaturated solution?
• 77
• Raise the temperature of the solvent while
adding the solute.
Question 38
• Regina performed two experiments. The first
experiment involved one gram of salt
dissolved in 200 milliliters of water. Her
second experiment involved one gram of salt
dissolved in 1 liter of water. In which
experiment did the solute dissolve faster?
Question 38
• Regina performed two experiments. The first
experiment involved one gram of salt
dissolved in 200 milliliters of water. Her
second experiment involved one gram of salt
dissolved in 1 liter of water. In which
experiment did the solute dissolve faster?
• The salt dissolved faster in the 1 L of water
Question 39
• Drain cleaners commonly used at home
contain NaOH (sodium hydroxide). This turns
red litmus paper blue. What is the nature of
these cleaners?
Question 39
• Drain cleaners commonly used at home
contain NaOH (sodium hydroxide). This turns
red litmus paper blue. What is the nature of
these cleaners?
• Basic (They are bases)
Question 40
• Determine which of the following substances
will not conduct electricity well when it is
dissolved in water.
Question 40
• Determine which of the following substances
will not conduct electricity well when it is
dissolved in water.
• covalent compounds
Question 41
• The pH of swimming pool water is maintained
at acidic levels to prevent the growth of algae
and bacteria. What conclusion can be drawn
from this information?
Question 41
• The pH of swimming pool water is maintained
at acidic levels to prevent the growth of algae
and bacteria. What conclusion can be drawn
from this information?
• Acidic water is harmful for the aquatic life in
natural systems.