Question 1

What would be the best explanation for the fact that most natural water has a pH of about 5.6?

Accepted Answer

A)  Carbon dioxide reacts with water to form an acid. 
B)  Air contains acid rain particles. 
C)  Minerals that are dissolved in water are often acidic. 
D)  Many salts that dissolve in natural waters make the water basic. 
E)  none of the above 
A)  Carbon dioxide reacts with water to form an acid. 
B)  Air contains acid rain particles. 
C)  Minerals that are dissolved in water are often acidic. 
D)  Many salts that dissolve in natural waters make the water basic. 
E)  none of the above

Question 2

Sodium hydroxide is added to a buffer solution of ammonia, N   , and ammonium chloride,   . What is the effect on the concentration of ammonia? What is the effect on the concentration of ammonium chloride?

Accepted Answer

A)  Sodium hydroxide reacts with both the ammonia and ammonium chloride, so the concentration of both decreases. 
B)  Sodium hydroxide reacts with only the ammonium chloride, so the concentration of the ammonium chloride decreases and the concentration of ammonia increases. 
C)  Sodium hydroxide reacts with both the ammonia and ammonium chloride, so the concentration of both increases. 
D)  Sodium hydroxide reacts with only the ammonia, so the concentration of the ammonium chloride increases and the concentration of ammonia decreases. 
A)  Sodium hydroxide reacts with both the ammonia and ammonium chloride, so the concentration of both decreases. 
B)  Sodium hydroxide reacts with only the ammonium chloride, so the concentration of the ammonium chloride decreases and the concentration of ammonia increases. 
C)  Sodium hydroxide reacts with both the ammonia and ammonium chloride, so the concentration of both increases. 
D)  Sodium hydroxide reacts with only the ammonia, so the concentration of the ammonium chloride increases and the concentration of ammonia decreases.

Question 3

Which of the following statements about buffers is untrue?

Accepted Answer

A)  The pH of a buffer solution cannot change. 
B)  Addition of small amounts of acid to a buffer changes the pH. 
C)  Addition of small amounts of base to a buffer changes the pH. 
D)  A salt from the reaction of a strong acid and a strong base can be used to make a buffer. 
E)  None of the above are true. 
A)  The pH of a buffer solution cannot change. 
B)  Addition of small amounts of acid to a buffer changes the pH. 
C)  Addition of small amounts of base to a buffer changes the pH. 
D)  A salt from the reaction of a strong acid and a strong base can be used to make a buffer. 
E)  None of the above are true.

Question 4

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

Accepted Answer

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

Question 5

Why are aqueous solutions of highly charged metal ions, such as   , usually acidic?

Accepted Answer

A)  The highly charged    ion strips hydrogen ions away from water as if forms   and releases them into the solution causing the solution to become acidic. 
B)  As the water molecule binds to the aluminum ion, the H-O bond becomes more polar. This means that the water molecule is more readily able to form hydrogen ions, which makes the solution acidic. 
C)  False!   ions tend to make aqueous solutions basic since they pull the OH⁻ ion from the water molecule. 
D)  The formation of the oxide     releases hydrogen ions to the aqueous solution making it acidic. 
A)  The highly charged    ion strips hydrogen ions away from water as if forms   and releases them into the solution causing the solution to become acidic. 
B)  As the water molecule binds to the aluminum ion, the H-O bond becomes more polar. This means that the water molecule is more readily able to form hydrogen ions, which makes the solution acidic. 
C)  False!   ions tend to make aqueous solutions basic since they pull the OH⁻ ion from the water molecule. 
D)  The formation of the oxide     releases hydrogen ions to the aqueous solution making it acidic.

Question 6

Which of the following statements describes a neutral solution?

Accepted Answer

A)  [H3O+] > [OH-] 
B)  [H3O+] -] 
C)  [H3O+] × [OH-] ≠ 1 × 10-14 
D)  [H3O+]/[OH-] = 1 × 10-14 
E)  [H3O+]/[OH-] = 1 
A)  [H3O+] > [OH-] 
B)  [H3O+] -] 
C)  [H3O+] × [OH-] ≠ 1 × 10-14 
D)  [H3O+]/[OH-] = 1 × 10-14 
E)  [H3O+]/[OH-] = 1

Question 7

What happens to the pH of soda water as it loses its carbonation?

Accepted Answer

A)  It does not change since the carbonation has nothing to do with pH. 
B)  It decreases as it loses the carbon dioxide molecules which form the carbonic acid in the soda. 
C)  It increases as it loses the carbon dioxide molecules which form the carbonic acid in the soda. 
D)  It decreases as the soda becomes more concentrated through the loss of the carbon dioxide gases. 
A)  It does not change since the carbonation has nothing to do with pH. 
B)  It decreases as it loses the carbon dioxide molecules which form the carbonic acid in the soda. 
C)  It increases as it loses the carbon dioxide molecules which form the carbonic acid in the soda. 
D)  It decreases as the soda becomes more concentrated through the loss of the carbon dioxide gases.

Question 8

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

Accepted Answer

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

Question 9

Which of the above images represents a solution of the strongest acid (HA)?

Accepted Answer

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

Question 10

When the hydronium ion concentration equals 10 moles per liter, what is the pH of the solution? Is the solution acidic or basic?

Accepted Answer

A)  pH = 0, this is an acidic solution. 
B)  pH = 1, this is an acidic solution. 
C)  pH = -0.301, this is an acidic solution. 
D)  pH = 7, this is a neutral solution. 
A)  pH = 0, this is an acidic solution. 
B)  pH = 1, this is an acidic solution. 
C)  pH = -0.301, this is an acidic solution. 
D)  pH = 7, this is a neutral solution.

Question 11

For the following acid-base reaction, identify which salt is formed. HCl + NaOH ⇌ ???? + H2O

Accepted Answer

A)  NaCl 
B)  H3OCl 
C)  NaOH2 
D)  NaOH2Cl 
E)  none of the above 
A)  NaCl 
B)  H3OCl 
C)  NaOH2 
D)  NaOH2Cl 
E)  none of the above

Question 12

If the pH of a solution is 10, what is the hydronium ion concentration?

Accepted Answer

A)  1 × 10-10 M 
B)  1 × 1010 M 
C)  10 M 
D)  -10 M 
E)  - 1 × 1010 M 
A)  1 × 10-10 M 
B)  1 × 1010 M 
C)  10 M 
D)  -10 M 
E)  - 1 × 1010 M

Question 13

Why is phosphoric acid,     , a stronger acid than disodium hydrogen phosphate,   ?

Accepted Answer

A)  Phosphoric acid has three acidic hydrogens which makes it three times as acidic. 
B)  Some of the released sodium ions in   HP   form NaOH (a base), which decreases the acidity of the   HP   . 
C)  Phosphoric acid dissociates 100% in water whereas   HP   only dissociates about 50%. 
D)  None of the above accurately describes why phosphoric acid is a stronger acid than disodium hydrogen phosphate. 
A)  Phosphoric acid has three acidic hydrogens which makes it three times as acidic. 
B)  Some of the released sodium ions in   HP   form NaOH (a base), which decreases the acidity of the   HP   . 
C)  Phosphoric acid dissociates 100% in water whereas   HP   only dissociates about 50%. 
D)  None of the above accurately describes why phosphoric acid is a stronger acid than disodium hydrogen phosphate.

Question 14

If the oceans became acidic, they would start to ________.

Accepted Answer

A)  absorb more CO2, which would make them even more acidic 
B)  release more CO2, which would raise the pH 
C)  absorb more CO2, which would raise the pH 
D)  release more CO2, which would make them even more acidic 
A)  absorb more CO2, which would make them even more acidic 
B)  release more CO2, which would raise the pH 
C)  absorb more CO2, which would raise the pH 
D)  release more CO2, which would make them even more acidic

Question 15

What would be the concentration of hydronium ions in a solution that had a pH = -3? Why would such a solution be impossible to prepare?

Accepted Answer

A)  Concentration of     = 3 M. It is impossible because it is hard to measure such a small amount of hydronium ions accurately. 
B)  Concentration of     = 30 M. It is impossible because pH can not be negative. 
C)  Concentration of     =   M. It is impossible because any container used to hold the acid would immediately corrode. 
D)  Concentration of     =   M. It is impossible because only so much acid can dissolve in water before the solution becomes saturated. 
A)  Concentration of     = 3 M. It is impossible because it is hard to measure such a small amount of hydronium ions accurately. 
B)  Concentration of     = 30 M. It is impossible because pH can not be negative. 
C)  Concentration of     =   M. It is impossible because any container used to hold the acid would immediately corrode. 
D)  Concentration of     =   M. It is impossible because only so much acid can dissolve in water before the solution becomes saturated.

Question 16

Which of the following solutions is the most acidic?

Accepted Answer

A)  a solution with a pH = 14 
B)  a solution with a pH = 12 
C)  a solution with a pH = 7 
D)  a solution with a pH = 13 
E)  All of the solutions are basic. 
A)  a solution with a pH = 14 
B)  a solution with a pH = 12 
C)  a solution with a pH = 7 
D)  a solution with a pH = 13 
E)  All of the solutions are basic.

Question 17

Why is carbon dioxide able to be stored more effectively in ocean water vs. fresh water?

Accepted Answer

A)  The pH of the ocean is pretty high and so the carbon dioxide is trapped in a neutralization reaction. 
B)  The oceans are large and so you can dissolve more CO2 in them. 
C)  Gases are more soluble in cold water than warm water and the oceans are colder than fresh water lakes so you can dissolve more CO2 in them. 
D)  The pH of the ocean is very low and so the carbon dioxide is trapped as an acid because like dissolves like. 
E)  none of the above 
A)  The pH of the ocean is pretty high and so the carbon dioxide is trapped in a neutralization reaction. 
B)  The oceans are large and so you can dissolve more CO2 in them. 
C)  Gases are more soluble in cold water than warm water and the oceans are colder than fresh water lakes so you can dissolve more CO2 in them. 
D)  The pH of the ocean is very low and so the carbon dioxide is trapped as an acid because like dissolves like. 
E)  none of the above

Question 18

What atom in the hydronium ion, H3O⁺, bears the positive charge?

Accepted Answer

A)  the hydrogen atom 
B)  the oxygen atom 
C)  Neither atom bears a positive charge. 
D)  Hydrogen and oxygen equally share the positive charge. 
A)  the hydrogen atom 
B)  the oxygen atom 
C)  Neither atom bears a positive charge. 
D)  Hydrogen and oxygen equally share the positive charge.

Question 19

If we were to lower our rate of CO2 production by a third-down from 9 to 6 billion tons per year-the concentration of CO2 in the atmosphere should ________.

Accepted Answer

A)  start to decrease 
B)  reach a steady state 
C)  continue to increase 
D)  It depends upon whether there are any major volcanic eruptions. 
A)  start to decrease 
B)  reach a steady state 
C)  continue to increase 
D)  It depends upon whether there are any major volcanic eruptions.

Question 20

What is a base?

Accepted Answer

A)  anything that accepts a hydrogen ion 
B)  anything that accepts a hydroxide ion 
C)  anything that donates a hydroxide ion 
D)  anything that can be used to clean drains 
E)  anything with a bitter taste 
A)  anything that accepts a hydrogen ion 
B)  anything that accepts a hydroxide ion 
C)  anything that donates a hydroxide ion 
D)  anything that can be used to clean drains 
E)  anything with a bitter taste

What would be the best explanation for the fact that most natural water has a pH of about 5.6?

Sodium hydroxide is added to a buffer solution of ammonia, N , and ammonium chloride, . What is the effect on the concentration of ammonia? What is the effect on the concentration of ammonium chloride?

Which of the following statements about buffers is untrue?

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

Why are aqueous solutions of highly charged metal ions, such as , usually acidic?

Which of the following statements describes a neutral solution?

What happens to the pH of soda water as it loses its carbonation?

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

Which of the above images represents a solution of the strongest acid (HA)?

When the hydronium ion concentration equals 10 moles per liter, what is the pH of the solution? Is the solution acidic or basic?

For the following acid-base reaction, identify which salt is formed. HCl + NaOH ⇌ ???? + H₂O

If the pH of a solution is 10, what is the hydronium ion concentration?

Why is phosphoric acid, , a stronger acid than disodium hydrogen phosphate, ?

If the oceans became acidic, they would start to ________.

What would be the concentration of hydronium ions in a solution that had a pH = -3? Why would such a solution be impossible to prepare?

Which of the following solutions is the most acidic?

Why is carbon dioxide able to be stored more effectively in ocean water vs. fresh water?

What atom in the hydronium ion, H₃O⁺, bears the positive charge?

If we were to lower our rate of CO₂ production by a third-down from 9 to 6 billion tons per year-the concentration of CO₂ in the atmosphere should ________.

What is a base?

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Exam 10: Acids and Bases in Our Environment

What would be the best explanation for the fact that most natural water has a pH of about 5.6?

Sodium hydroxide is added to a buffer solution of ammonia, N , and ammonium chloride, . What is the effect on the concentration of ammonia? What is the effect on the concentration of ammonium chloride?

Which of the following statements about buffers is untrue?

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

Why are aqueous solutions of highly charged metal ions, such as , usually acidic?

Which of the following statements describes a neutral solution?

What happens to the pH of soda water as it loses its carbonation?

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

Which of the above images represents a solution of the strongest acid (HA)?

When the hydronium ion concentration equals 10 moles per liter, what is the pH of the solution? Is the solution acidic or basic?

For the following acid-base reaction, identify which salt is formed. HCl + NaOH ⇌ ???? + H2O

If the pH of a solution is 10, what is the hydronium ion concentration?

Why is phosphoric acid, , a stronger acid than disodium hydrogen phosphate, ?

If the oceans became acidic, they would start to ________.

What would be the concentration of hydronium ions in a solution that had a pH = -3? Why would such a solution be impossible to prepare?

Which of the following solutions is the most acidic?

Why is carbon dioxide able to be stored more effectively in ocean water vs. fresh water?

What atom in the hydronium ion, H3O⁺, bears the positive charge?

If we were to lower our rate of CO2 production by a third-down from 9 to 6 billion tons per year-the concentration of CO2 in the atmosphere should ________.

What is a base?

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

Oxidations and Reductions Charge the World

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

Filters

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

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

For the following acid-base reaction, identify which salt is formed. HCl + NaOH ⇌ ???? + H₂O

What atom in the hydronium ion, H₃O⁺, bears the positive charge?

If we were to lower our rate of CO₂ production by a third-down from 9 to 6 billion tons per year-the concentration of CO₂ in the atmosphere should ________.