CEM 141 Final Exam Study Guide-Question with Correct Answers/
Verified
heat from a fire. - ✔️✔️Which of the Following is not an example of Matter?
Grow the tree in a pot and measure the mass of the soil before and after the tree grows a certain
height. - ✔️✔️In answer to the question, "When a plant grows, where does the material come
from?" the ancient Greek philosopher Aristotle hypothesized by logic that all material came from the
soil. Which of the following experimental tests might best support Aristotle's hypothesis or show it
to be incorrect?
It can be used to make predictions that can be tested with experiments, it can change as new
evidence becomes available, it explains why a phenomena happens. - ✔️✔️What is true about
scientific theory?
It disproved the postulate "elements are composed of small indivisible, indestructible particles called
atoms" because electrons show atoms have smaller parts. - ✔️✔️Thomson's discovery of the
electron affected Dalton's atomic theory in what way?
False, Atoms of an element may have a different number of neutrons and therefore have different
masses and properties. - ✔️✔️"All atoms of an element are identical and have the same mass and
properties." Is that true or false and why?
Protons and neutrons are found in the nucleus. - ✔️✔️Which of the following statements about the
composition of an atom could not be inferred based on Rutherford's gold foil experiment?
There is no mention of a field, and a single object cannot have potential energy. - ✔️✔️What is
wrong with the statement: "As your clicker falls to the floor, the potential energy of your clicker
decreases."
Energy is just released. - ✔️✔️What will happen to the energy in the system when this reaction
occurs: 2 H (g) --> H2 (g)?
They will collide with the sides of the pot, and the atoms in the pot are directly heated from the
stove burner. - ✔️✔️Water in a pot on a stove burner will warn up and eventually boil. How do the
water molecules know that the temperature is increasing?
, Claim: I2 has stronger attractive forces between molecules than Br2
Reasoning: I2 has a larger electron cloud and stronger LDFs than Br2 which require more energy to
overcome when it melts. - ✔️✔️Using the following evidence, what claim and reasoning can you
make?
Evidence: The melting point of I2 is 114 C and the melting point of Br2 is -7.2 C.
The electron clouds of Ar atoms are larger than He, and can form larger temporary dipoles, the
forces pf attraction between Ar atoms are larger, and more energy is required to separate Ar atoms.
- ✔️✔️Ar has a higher melting point than He because:
None of the above - ✔️✔️What statement is correct for the electrostatic force, but incorrect for the
gravitational force?
A. The force strength decreases with an increase in separation distance
B. The force strength is zero at infinite separation distance
C. The force is always attractive
D. It is a fundamental force
E. None of the above
Decrease, because the particles are attracted to each other. - ✔️✔️As an electron and a proton
move towards each other, the potential energy of the system will:
LDFs are overcome, energy is absorbed from the surroundings, and energy is transferred via
collisions. - ✔️✔️When liquid oxygen (O2) warms up, eventually it evaporates. Which of these best
explains the forces and energy changes that take place during this process.
One gram of Fe2O3 reacts with 2 grams of Al to form 1 gram of Al2O3 and 2 grams of Fe. -
✔️✔️Which pf the following is NOT a correct interpretation of the following balanced chemical
equation?
Fe2O3 (s) + 2 Al (s) --> Al2O3 (s) + 2 Fe (s)
5.4 mol - ✔️✔️If 9.0 moles of oxygen gas are consumed with excess propane in the following
reaction, how many moles of carbon dioxide will be produced?
C3H8 (g) + 5 O2 (g) --> 3 CO2 (g) + 4 H20 (g)
Verified
heat from a fire. - ✔️✔️Which of the Following is not an example of Matter?
Grow the tree in a pot and measure the mass of the soil before and after the tree grows a certain
height. - ✔️✔️In answer to the question, "When a plant grows, where does the material come
from?" the ancient Greek philosopher Aristotle hypothesized by logic that all material came from the
soil. Which of the following experimental tests might best support Aristotle's hypothesis or show it
to be incorrect?
It can be used to make predictions that can be tested with experiments, it can change as new
evidence becomes available, it explains why a phenomena happens. - ✔️✔️What is true about
scientific theory?
It disproved the postulate "elements are composed of small indivisible, indestructible particles called
atoms" because electrons show atoms have smaller parts. - ✔️✔️Thomson's discovery of the
electron affected Dalton's atomic theory in what way?
False, Atoms of an element may have a different number of neutrons and therefore have different
masses and properties. - ✔️✔️"All atoms of an element are identical and have the same mass and
properties." Is that true or false and why?
Protons and neutrons are found in the nucleus. - ✔️✔️Which of the following statements about the
composition of an atom could not be inferred based on Rutherford's gold foil experiment?
There is no mention of a field, and a single object cannot have potential energy. - ✔️✔️What is
wrong with the statement: "As your clicker falls to the floor, the potential energy of your clicker
decreases."
Energy is just released. - ✔️✔️What will happen to the energy in the system when this reaction
occurs: 2 H (g) --> H2 (g)?
They will collide with the sides of the pot, and the atoms in the pot are directly heated from the
stove burner. - ✔️✔️Water in a pot on a stove burner will warn up and eventually boil. How do the
water molecules know that the temperature is increasing?
, Claim: I2 has stronger attractive forces between molecules than Br2
Reasoning: I2 has a larger electron cloud and stronger LDFs than Br2 which require more energy to
overcome when it melts. - ✔️✔️Using the following evidence, what claim and reasoning can you
make?
Evidence: The melting point of I2 is 114 C and the melting point of Br2 is -7.2 C.
The electron clouds of Ar atoms are larger than He, and can form larger temporary dipoles, the
forces pf attraction between Ar atoms are larger, and more energy is required to separate Ar atoms.
- ✔️✔️Ar has a higher melting point than He because:
None of the above - ✔️✔️What statement is correct for the electrostatic force, but incorrect for the
gravitational force?
A. The force strength decreases with an increase in separation distance
B. The force strength is zero at infinite separation distance
C. The force is always attractive
D. It is a fundamental force
E. None of the above
Decrease, because the particles are attracted to each other. - ✔️✔️As an electron and a proton
move towards each other, the potential energy of the system will:
LDFs are overcome, energy is absorbed from the surroundings, and energy is transferred via
collisions. - ✔️✔️When liquid oxygen (O2) warms up, eventually it evaporates. Which of these best
explains the forces and energy changes that take place during this process.
One gram of Fe2O3 reacts with 2 grams of Al to form 1 gram of Al2O3 and 2 grams of Fe. -
✔️✔️Which pf the following is NOT a correct interpretation of the following balanced chemical
equation?
Fe2O3 (s) + 2 Al (s) --> Al2O3 (s) + 2 Fe (s)
5.4 mol - ✔️✔️If 9.0 moles of oxygen gas are consumed with excess propane in the following
reaction, how many moles of carbon dioxide will be produced?
C3H8 (g) + 5 O2 (g) --> 3 CO2 (g) + 4 H20 (g)
