Question 1

Upon combustion, about how many grams of water vapor are produced from every 16 grams of methane,   ? 
  + 2   →   + 2   O

Accepted Answer

A) 16 grams 
B) 18 grams 
C) 36 grams 
D) 8 grams 
A) 16 grams 
B) 18 grams 
C) 36 grams 
D) 8 grams

Question 2

How does an atom's electronegativity relate to its ability to become oxidized?

Accepted Answer

A) The greater the electronegativity of an atom, the greater its ability to become oxidized. 
B) The lower the electronegativity of an atom, the lower its ability to become oxidized. 
C) The greater the electronegativity of an atom, the lower its ability to become oxidized. 
D) Electronegativity does not effect the atom's ability to become oxidized. 
A) The greater the electronegativity of an atom, the greater its ability to become oxidized. 
B) The lower the electronegativity of an atom, the lower its ability to become oxidized. 
C) The greater the electronegativity of an atom, the lower its ability to become oxidized. 
D) Electronegativity does not effect the atom's ability to become oxidized.

Question 3

Chemical equations need to be balanced not only in terms of the number of atoms, but also by the charge. In other words, just as there should be the same number of atoms before and after the arrow of an equation, there should be the same charge. What set of coefficients is necessary to balance the following chemical equation? ____   + ____ Ag → ____ Sn + ____ Ag⁺

Accepted Answer

A) 1, 2, 1, 2 
B) 1, 1, 1, 2 
C) 1, 2, 2, 2 
D) 1, 1, 2, 1 
A) 1, 2, 1, 2 
B) 1, 1, 1, 2 
C) 1, 2, 2, 2 
D) 1, 1, 2, 1

Question 4

Chemical equations need to be balanced not only in terms of the number of atoms, but also by the charge. In other words, just as there should be the same number of atoms before and after the arrow of an equation, there should be the same charge. What set of coefficients is necessary to balance the following chemical equation? ____   + ____ Cl⁻ → ____   + ____

Accepted Answer

A) 1, 2, 1, 1 
B) 2, 2, 2, 1 
C) 1, 4, 1, 2 
D) 3, 4, 3, 2 
A) 1, 2, 1, 1 
B) 2, 2, 2, 1 
C) 1, 4, 1, 2 
D) 3, 4, 3, 2

Question 5

What is oxidation?

Accepted Answer

A) the loss of electrons 
B) the reaction with oxygen 
C) the reduction of oxygen 
D) the gaining of electrons 
E) the addition of an electron to the valence shell 
A) the loss of electrons 
B) the reaction with oxygen 
C) the reduction of oxygen 
D) the gaining of electrons 
E) the addition of an electron to the valence shell

Question 6

What might the relationship be between an element's electronegativity and its ability to behave as an oxidizing agent?

Accepted Answer

A) As the electronegativity increases the ability of an element to act as an oxidizing agent increases. 
B) As the electronegativity increases the ability of an element to act as an oxidizing agent decreases. 
C) As the electronegativity increases the ability of an element to act as an oxidizing agent stays the same. 
D) none of the above 
A) As the electronegativity increases the ability of an element to act as an oxidizing agent increases. 
B) As the electronegativity increases the ability of an element to act as an oxidizing agent decreases. 
C) As the electronegativity increases the ability of an element to act as an oxidizing agent stays the same. 
D) none of the above

Question 7

Which of the half-reactions below would be complementary, balance the following half-reaction, and be chemically reasonable? Br2 → 2 Br-

Accepted Answer

A) 2 K → 2 K+ 
B) K+ → K 
C) K → K+ 
D) 2 K+ → 2 K 
E) K → K2+ 
A) 2 K → 2 K+ 
B) K+ → K 
C) K → K+ 
D) 2 K+ → 2 K 
E) K → K2+

Question 8

Which element is closer to the upper right corner of the periodic table, the one indicated by the lighter colored atoms or the darker colored atoms?

Accepted Answer

A) the element indicated by the darker color 
B) the element indicated by the lighter color 
C) More information is needed in order to determine which element is closer to the upper right of the periodic table. 
D) Both the lighter and darker colored elements are likely found at the upper right corner of the periodic table. 
A) the element indicated by the darker color 
B) the element indicated by the lighter color 
C) More information is needed in order to determine which element is closer to the upper right of the periodic table. 
D) Both the lighter and darker colored elements are likely found at the upper right corner of the periodic table.

Question 9

Iron atoms have a greater tendency to oxidize than do copper atoms. Is this good news or bad news for a home in which much of the plumbing consists of iron and copper pipes connected together? Explain.

Accepted Answer

A) This is bad news, since the iron atoms will be reduced by the copper atoms. 
B) This is not a problem, since the strength of the copper will make up for the weakness of the iron. 
C) It is bad news. The iron atoms will lose electrons to the copper atoms, which will pass those electrons onto oxygen atoms that are in contact with the surface. 
D) This is not a problem since any electrons lost will be replaced by copper electrons. 
A) This is bad news, since the iron atoms will be reduced by the copper atoms. 
B) This is not a problem, since the strength of the copper will make up for the weakness of the iron. 
C) It is bad news. The iron atoms will lose electrons to the copper atoms, which will pass those electrons onto oxygen atoms that are in contact with the surface. 
D) This is not a problem since any electrons lost will be replaced by copper electrons.

Question 10

Why is it easier for the body to excrete a polar molecule than it is to excrete a nonpolar molecule? What chemistry does the body use to get rid of molecules it no longer needs?

Accepted Answer

A) It is easier for the body to excrete non-polar molecules because they dissolve in the oils of the skin and are washed away when we bathe. 
B) Polar molecules are easier to excrete because of their greater solubility in water. Upon dissolving in water, they can be excreted through urine. 
C) Polarity of the molecules has nothing to do with the ease of excretion. However, the body does metabolize and excrete smaller molecules more easily and passes them out through the colon. 
D) Polar and non-polar molecules are excreted equally easily. The body is well adapted to deal with both forms of molecules via its metabolic processes. 
A) It is easier for the body to excrete non-polar molecules because they dissolve in the oils of the skin and are washed away when we bathe. 
B) Polar molecules are easier to excrete because of their greater solubility in water. Upon dissolving in water, they can be excreted through urine. 
C) Polarity of the molecules has nothing to do with the ease of excretion. However, the body does metabolize and excrete smaller molecules more easily and passes them out through the colon. 
D) Polar and non-polar molecules are excreted equally easily. The body is well adapted to deal with both forms of molecules via its metabolic processes.

Question 11

A major source of chlorine gas,   , is from the electrolysis of brine, which is concentrated salt water,   Which of the following is the balanced chemical reaction for this electrolysis reaction?

Accepted Answer

A) 2 NaCl (aq)+ 2 H2O → 2 NaOH (aq)+   (g)+ 2   (g) 
B) 2 NaCl (aq)+   O →   O (aq)+ 2 HCl (aq) 
C) 2 NaCl (aq)+ 2   O → 2 Na (s)+ O2 (g)+ 2   (g)+   (g) 
D) 2 NaCl (aq)+   O → 2 NaH (aq)+   O⁻ (aq) 
A) 2 NaCl (aq)+ 2 H2O → 2 NaOH (aq)+   (g)+ 2   (g) 
B) 2 NaCl (aq)+   O →   O (aq)+ 2 HCl (aq) 
C) 2 NaCl (aq)+ 2   O → 2 Na (s)+ O2 (g)+ 2   (g)+   (g) 
D) 2 NaCl (aq)+   O → 2 NaH (aq)+   O⁻ (aq)

Question 12

Which of the following statements describes what happens when you press a n-type silicon wafer against a p-type silicon wafer?

Accepted Answer

A) The n-type wafer becomes slightly positive, while the p-type becomes slightly negative. 
B) The p-type wafer becomes slightly positive, while the n-type becomes slightly negative. 
C) There is no change. 
D) They both become slightly negative. 
E) They both become slightly positive. 
A) The n-type wafer becomes slightly positive, while the p-type becomes slightly negative. 
B) The p-type wafer becomes slightly positive, while the n-type becomes slightly negative. 
C) There is no change. 
D) They both become slightly negative. 
E) They both become slightly positive.

Question 13

What is the primary difference between a fuel cell and a battery?

Accepted Answer

A) Fuel cells do not run down because they can be refueled; batteries run down and need to be recharged. 
B) Batteries can be recharged, fuel cells cannot. 
C) Batteries supply electricity; fuel cells supply heat. 
D) Fuel cells oxidize to supply electricity, batteries reduce to supply electricity. 
E) Fuel cells do not use metals as oxidants and reductants, batteries have a static reservoir of oxidant and reductant. 
A) Fuel cells do not run down because they can be refueled; batteries run down and need to be recharged. 
B) Batteries can be recharged, fuel cells cannot. 
C) Batteries supply electricity; fuel cells supply heat. 
D) Fuel cells oxidize to supply electricity, batteries reduce to supply electricity. 
E) Fuel cells do not use metals as oxidants and reductants, batteries have a static reservoir of oxidant and reductant.

Question 14

A battery operates by ________.

Accepted Answer

A) oxidation 
B) reduction 
C) both oxidation and reduction 
D) none of the above 
A) oxidation 
B) reduction 
C) both oxidation and reduction 
D) none of the above

Question 15

How is the junction barrier between n-type and p-type silicon much like a one-way valve?

Accepted Answer

A) The electrons can only be lost from the p-type silicon wafer. 
B) The orientation of the charge around the barrier allows the electrons to flow in only one direction. 
C) The electrons can only be lost from the n-type silicon wafer. 
D) Only one side of the barrier is exposed to light, which causes the electrons to flow in the opposite direction. 
A) The electrons can only be lost from the p-type silicon wafer. 
B) The orientation of the charge around the barrier allows the electrons to flow in only one direction. 
C) The electrons can only be lost from the n-type silicon wafer. 
D) Only one side of the barrier is exposed to light, which causes the electrons to flow in the opposite direction.

Question 16

The elements that make the best reducing agents are the ________.

Accepted Answer

A) group 18 noble gases 
B) group 17 halogens 
C) transition metals 
D) group 1 alkali metals 
A) group 18 noble gases 
B) group 17 halogens 
C) transition metals 
D) group 1 alkali metals

Question 17

What is one of the advantages of a fuel cell?

Accepted Answer

A) They can run for a very long time as long as you keep adding fuel. 
B) They are more efficient than combustion. 
C) They have lower emission of pollutants than combustion. 
D) all of the above 
E) only A and B 
A) They can run for a very long time as long as you keep adding fuel. 
B) They are more efficient than combustion. 
C) They have lower emission of pollutants than combustion. 
D) all of the above 
E) only A and B

Question 18

Glucose,   , is a simple sugar that the body metabolizes into two molecules of pyruvic acid,   . Is the glucose oxidized or reduced as it transforms into pyruvic acid?

Accepted Answer

A) The glucose is oxidized. 
B) The glucose is reduced. 
C) Parts of the glucose molecule are oxidized while others are reduced. 
D) Glucose is neither oxidized or reduced as it transforms into pyruvic acid. 
A) The glucose is oxidized. 
B) The glucose is reduced. 
C) Parts of the glucose molecule are oxidized while others are reduced. 
D) Glucose is neither oxidized or reduced as it transforms into pyruvic acid.

Question 19

In an operating photovoltaic cell, electrons move through the external circuit to the negatively charged p-type silicon wafer. How can the electrons move to the negatively charged silicon when they themselves are negatively charged? Don't like signs repel each other?

Accepted Answer

A) This is a technological hurdle that has greatly inhibited the advancement of photovoltaic technology. 
B) An electric current is possible because the energy from the sun momentarily reverses the charge of the electrons, which are then called positrons (p-type). 
C) The p-type silicon wafer is actually positively charged. 
D) The energy of the sunlight knocks the electrons into a direction that they would otherwise not go. 
A) This is a technological hurdle that has greatly inhibited the advancement of photovoltaic technology. 
B) An electric current is possible because the energy from the sun momentarily reverses the charge of the electrons, which are then called positrons (p-type). 
C) The p-type silicon wafer is actually positively charged. 
D) The energy of the sunlight knocks the electrons into a direction that they would otherwise not go.

Question 20

What might the relationship be between an element's ionization energy and its ability to behave as an oxidizing agent?

Accepted Answer

A) As the ionization energy increases, the ability of an element to act as an oxidizing agent increases. 
B) As the ionization energy increases, the ability of an element to act as an oxidizing agent decreases. 
C) As the ionization energy increases, the ability of an element to act as an oxidizing agent stays the same. 
D) none of the above 
A) As the ionization energy increases, the ability of an element to act as an oxidizing agent increases. 
B) As the ionization energy increases, the ability of an element to act as an oxidizing agent decreases. 
C) As the ionization energy increases, the ability of an element to act as an oxidizing agent stays the same. 
D) none of the above

Upon combustion, about how many grams of water vapor are produced from every 16 grams of methane, ? + 2 → + 2 O

How does an atom's electronegativity relate to its ability to become oxidized?

What is oxidation?

What might the relationship be between an element's electronegativity and its ability to behave as an oxidizing agent?

Which of the half-reactions below would be complementary, balance the following half-reaction, and be chemically reasonable? Br₂ → 2 Br^-

Which element is closer to the upper right corner of the periodic table, the one indicated by the lighter colored atoms or the darker colored atoms?

Iron atoms have a greater tendency to oxidize than do copper atoms. Is this good news or bad news for a home in which much of the plumbing consists of iron and copper pipes connected together? Explain.

Why is it easier for the body to excrete a polar molecule than it is to excrete a nonpolar molecule? What chemistry does the body use to get rid of molecules it no longer needs?

A major source of chlorine gas, , is from the electrolysis of brine, which is concentrated salt water, Which of the following is the balanced chemical reaction for this electrolysis reaction?

Which of the following statements describes what happens when you press a n-type silicon wafer against a p-type silicon wafer?

What is the primary difference between a fuel cell and a battery?

A battery operates by ________.

How is the junction barrier between n-type and p-type silicon much like a one-way valve?

The elements that make the best reducing agents are the ________.

What is one of the advantages of a fuel cell?

Glucose, , is a simple sugar that the body metabolizes into two molecules of pyruvic acid, . Is the glucose oxidized or reduced as it transforms into pyruvic acid?

In an operating photovoltaic cell, electrons move through the external circuit to the negatively charged p-type silicon wafer. How can the electrons move to the negatively charged silicon when they themselves are negatively charged? Don't like signs repel each other?

What might the relationship be between an element's ionization energy and its ability to behave as an oxidizing agent?

About Science

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Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

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Nutrients of Life

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Exam 11: Oxidations and Reductions Charge the World

Upon combustion, about how many grams of water vapor are produced from every 16 grams of methane, ? + 2 → + 2 O

How does an atom's electronegativity relate to its ability to become oxidized?

What is oxidation?

What might the relationship be between an element's electronegativity and its ability to behave as an oxidizing agent?

Which of the half-reactions below would be complementary, balance the following half-reaction, and be chemically reasonable? Br2 → 2 Br-

Which element is closer to the upper right corner of the periodic table, the one indicated by the lighter colored atoms or the darker colored atoms?

Iron atoms have a greater tendency to oxidize than do copper atoms. Is this good news or bad news for a home in which much of the plumbing consists of iron and copper pipes connected together? Explain.

Why is it easier for the body to excrete a polar molecule than it is to excrete a nonpolar molecule? What chemistry does the body use to get rid of molecules it no longer needs?

A major source of chlorine gas, , is from the electrolysis of brine, which is concentrated salt water, Which of the following is the balanced chemical reaction for this electrolysis reaction?

Which of the following statements describes what happens when you press a n-type silicon wafer against a p-type silicon wafer?

What is the primary difference between a fuel cell and a battery?

A battery operates by ________.

How is the junction barrier between n-type and p-type silicon much like a one-way valve?

The elements that make the best reducing agents are the ________.

What is one of the advantages of a fuel cell?

Glucose, , is a simple sugar that the body metabolizes into two molecules of pyruvic acid, . Is the glucose oxidized or reduced as it transforms into pyruvic acid?

In an operating photovoltaic cell, electrons move through the external circuit to the negatively charged p-type silicon wafer. How can the electrons move to the negatively charged silicon when they themselves are negatively charged? Don't like signs repel each other?

What might the relationship be between an element's ionization energy and its ability to behave as an oxidizing agent?

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

How Molecules Mix

How Water Behaves

How Chemicals React

Acids and Bases in Our Environment

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

Filters

Which of the half-reactions below would be complementary, balance the following half-reaction, and be chemically reasonable? Br₂ → 2 Br^-