Question 1

Which of the following statements about oxidation and reduction reactions is true?

Accepted Answer

A)  More than one electron can be transferred in an oxidation and reduction reaction.
B)  In a half-reaction, only half of an electron is transferred.
C)  Only neutral atoms are formed in oxidation and reduction reactions.
D)  A half-reaction is only used for reduction reactions.
E)  None of the above are true. A

Question 2

Which of the following materials is most likely to act as an oxidizing agent?

Accepted Answer

A)  Na
B)  Na+
C)  Cl2
D)  Cl-
E)  both A and B C

Question 3

What is the main characteristic of a strong acid?

Accepted Answer

A)  It is completely dissociated in water.
B)  It readily gives up its proton to a base.
C)  It is corrosive.
D)  It will damage your skin.
E)  all of the above E

Question 4

If you had a 1 M solution of a weak acid what would be its pH?

Accepted Answer

A)  0
B)  6
C)  7
D)  8
E)  13

Question 5

Which of the following materials is most likely to undergo oxidation?

Accepted Answer

A)  Na
B)  Na+
C)  Cl2
D)  Cl-
E)  both A and B

Question 6

In one type of fuel cell, the following oxidation-reduction reactions are taking place: 2 H2 + O2 → 2 H2O
What is the oxidant?

Accepted Answer

A)  H2
B)  O2
C)  H2O
D)  all of the above
E)  none of the above

Question 7

For the following reaction, identify whether the compound in bold is behaving as an acid or a base. H3PO4 + H2O ⇌ H2PO4- + H3O+

Accepted Answer

A)  acid
B)  base
C)  neither
D)  both
E)  none of the above

Question 8

How many electrons are transferred from iron atoms to oxygen atoms in the formation of two molecules of iron hydroxide, Fe(OH)2?

Accepted Answer

A)  4 electrons
B)  8 electrons
C)  16 electrons
D)  12 electrons

Question 9

In the above diagram, which atom is oxidized, the darker colored atom or the lighter colored atom?

Accepted Answer

A)  Both of the atoms are oxidized.
B)  Neither of the atoms is oxidized.
C)  Only the darker colored atom is oxidized.
D)  Only the lighter colored atom is oxidized.

Question 10

Which of the above images would best describe a water solution of a weak acid (HA)the best?

Accepted Answer

A)  A
B)  B
C)  C
D)  All of the above are weak acids.
E)  None of the above are weak acids.

Question 11

Suggest why people once washed their hands with ashes.

Accepted Answer

A)  The ashes act as a base and reacts with skin oils to produce solutions of soap.
B)  The ashes act as an acid and reacts with the skin oils to produce soap.
C)  The oils on the skin act as a base and reacts with the ashes to produce soap.
D)  After being burnt in the fire, the acids and bases of the log are neutralized, making it a gentle material to use on the hands.

Question 12

How many electrons are gained or lost in the following half-reaction? 2 Na → 2 Na+

Accepted Answer

A)  2 electrons are lost
B)  1/2 electron is gained
C)  1/2 electron is lost
D)  2 electrons are gained
E)  4 electrons are gained

Question 13

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

Question 14

According to the following reaction, which molecule is acting as an acid? H2O + H2SO4 → H3O+ + HSO4-

Accepted Answer

A)  H2SO4
B)  H2O
C)  H3O+
D)  HSO4-
E)  none of the above

Question 15

Sodium hydroxide, NaOH, is a strong base, which means that it readily accepts hydrogen ions. What products are formed when sodium hydroxide accepts a hydrogen ion from a water molecule?

Accepted Answer

A)  water and sodium hydroxide
B)  sodium hydroxide and hydronium ions
C)  sodium ions and hydronium ions
D)  sodium ions and water

Question 16

Upon ingestion, grain alcohol, C2H6O, is metabolized into acetaldehyde, C2H4O, which is a toxic substance causing headaches as well as joint pains typical of a "hangover." Is the grain alcohol oxidized or reduced as it transforms into acetaldehyde?

Accepted Answer

A)  The grain alcohol is reduced.
B)  The grain alcohol is oxidized.
C)  Some of the grain alcohol is oxidized and some is reduced to other products.
D)  The grain alcohol is neither oxidized nor reduced.

Question 17

Which of the following species is the reducing agent? 2 CuBr → 2Cu + Br2

Accepted Answer

A)  Cu
B)  CuBr
C)  Cu+
D)  Br-
E)  Br2

Question 18

If you had a 1 M solution of a strong acid what would be its pH?

Accepted Answer

A)  0
B)  1
C)  7
D)  8
E)  13

Question 19

Which of the following statements is untrue about oxidation and reduction processes?

Accepted Answer

A)  An oxidation can happen without a reduction.
B)  It involves the exchange of electrons.
C)  Often ions are generated or consumed.
D)  Electrons are often involved in oxidation and reduction reactions.
E)  All of the above are true.

Question 20

In the reaction below, what does the symbol ⇌ mean? OH- + NH4+ ⇌ H2O + NH3

Accepted Answer

A)  It means that the forward and backward reactions are happening at the same time.
B)  It means that the reaction cannot decide which way to go.
C)  It means that the forward reaction does not progress.
D)  It means that the backward reaction happens as fast as the forward reaction and so the proton is not transferred at all.
E)  none of the above

Exam 18: Two Classes of Chemical Reactions

Which of the following statements about oxidation and reduction reactions is true?

Which of the following materials is most likely to act as an oxidizing agent?

What is the main characteristic of a strong acid?

If you had a 1 M solution of a weak acid what would be its pH?

Which of the following materials is most likely to undergo oxidation?

In one type of fuel cell, the following oxidation-reduction reactions are taking place: 2 H₂+ O₂ → 2 H₂O What is the oxidant?

For the following reaction, identify whether the compound in bold is behaving as an acid or a base. H₃PO₄ + H₂O ⇌ H₂PO₄^- + H₃O⁺

How many electrons are transferred from iron atoms to oxygen atoms in the formation of two molecules of iron hydroxide, Fe(OH) ₂?

In the above diagram, which atom is oxidized, the darker colored atom or the lighter colored atom?

Which of the above images would best describe a water solution of a weak acid (HA) the best?

Suggest why people once washed their hands with ashes.

How many electrons are gained or lost in the following half-reaction? 2 Na → 2 Na⁺

What is oxidation?

According to the following reaction, which molecule is acting as an acid? H₂O + H₂SO₄ → H₃O⁺ + HSO₄^-

Sodium hydroxide, NaOH, is a strong base, which means that it readily accepts hydrogen ions. What products are formed when sodium hydroxide accepts a hydrogen ion from a water molecule?

Upon ingestion, grain alcohol, C₂H₆O, is metabolized into acetaldehyde, C₂H₄O, which is a toxic substance causing headaches as well as joint pains typical of a "hangover." Is the grain alcohol oxidized or reduced as it transforms into acetaldehyde?

Which of the following species is the reducing agent? 2 CuBr → 2Cu + Br₂

If you had a 1 M solution of a strong acid what would be its pH?

Which of the following statements is untrue about oxidation and reduction processes?

In the reaction below, what does the symbol ⇌ mean? OH^- + NH₄⁺ ⇌ H₂O + NH₃

Exam 18: Two Classes of Chemical Reactions

Which of the following statements about oxidation and reduction reactions is true?

Which of the following materials is most likely to act as an oxidizing agent?

What is the main characteristic of a strong acid?

If you had a 1 M solution of a weak acid what would be its pH?

Which of the following materials is most likely to undergo oxidation?

In one type of fuel cell, the following oxidation-reduction reactions are taking place: 2 H2 + O2 → 2 H2O What is the oxidant?

For the following reaction, identify whether the compound in bold is behaving as an acid or a base. H3PO4 + H2O ⇌ H2PO4- + H3O+

How many electrons are transferred from iron atoms to oxygen atoms in the formation of two molecules of iron hydroxide, Fe(OH) 2?

In the above diagram, which atom is oxidized, the darker colored atom or the lighter colored atom?

Which of the above images would best describe a water solution of a weak acid (HA) the best?

Suggest why people once washed their hands with ashes.

How many electrons are gained or lost in the following half-reaction? 2 Na → 2 Na+

What is oxidation?

According to the following reaction, which molecule is acting as an acid? H2O + H2SO4 → H3O+ + HSO4-

Sodium hydroxide, NaOH, is a strong base, which means that it readily accepts hydrogen ions. What products are formed when sodium hydroxide accepts a hydrogen ion from a water molecule?

Upon ingestion, grain alcohol, C2H6O, is metabolized into acetaldehyde, C2H4O, which is a toxic substance causing headaches as well as joint pains typical of a "hangover." Is the grain alcohol oxidized or reduced as it transforms into acetaldehyde?

Which of the following species is the reducing agent? 2 CuBr → 2Cu + Br2

If you had a 1 M solution of a strong acid what would be its pH?

Which of the following statements is untrue about oxidation and reduction processes?

In the reaction below, what does the symbol ⇌ mean? OH- + NH4+ ⇌ H2O + NH3

In one type of fuel cell, the following oxidation-reduction reactions are taking place: 2 H₂+ O₂ → 2 H₂O What is the oxidant?

For the following reaction, identify whether the compound in bold is behaving as an acid or a base. H₃PO₄ + H₂O ⇌ H₂PO₄^- + H₃O⁺

How many electrons are transferred from iron atoms to oxygen atoms in the formation of two molecules of iron hydroxide, Fe(OH) ₂?

How many electrons are gained or lost in the following half-reaction? 2 Na → 2 Na⁺

According to the following reaction, which molecule is acting as an acid? H₂O + H₂SO₄ → H₃O⁺ + HSO₄^-

Upon ingestion, grain alcohol, C₂H₆O, is metabolized into acetaldehyde, C₂H₄O, which is a toxic substance causing headaches as well as joint pains typical of a "hangover." Is the grain alcohol oxidized or reduced as it transforms into acetaldehyde?

Which of the following species is the reducing agent? 2 CuBr → 2Cu + Br₂

In the reaction below, what does the symbol ⇌ mean? OH^- + NH₄⁺ ⇌ H₂O + NH₃