Question 1

What is one of the drawbacks to using fuel cells?

Accepted Answer

A) The fuel of the fuel cells is hard to handle. 
B) They are less efficient than combustion energy sources or batteries. 
C) They are very big and bulky,which makes them hard to use in small devices. 
D) There are no drawbacks. 
E) only A and B

Question 2

Which of the half-reactions below would be complementary and balance the following half-reaction? Zn+2 → Zn

Accepted Answer

A) Cu → Cu+2 
B) K+ → K 
C) 2 Cu → 2 Cu+2 
D) 2 K+ → 2 K 
E) Cl2 → 2 Cl-

Question 3

How would connecting iron with a wire to a piece of metal like copper,which undergoes reduction very easily,affect the rate at which the iron corrodes?

Accepted Answer

A) It would increase the rate of corrosion. 
B) It would decrease the rate of corrosion. 
C) The rate would stay the same. 
D) Rates are only affected by temperature. 
E) none of the above

Question 4

How might you tell whether or not your toothpaste contained either calcium carbonate,CaC $\mathrm { O } _ { 3 }$ ,or baking soda,NaHC $\mathrm { O } _ { 3 }$ ,without looking at the ingredients label?

Accepted Answer

A) if the toothpaste bubbles when heated 
B) if the toothpaste bubbles when added to ammonia,such as window cleaner 
C) if the toothpaste produces a salt (NaCl)when added to HCl 
D) if the toothpaste bubbles when added to vinegar

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

For the following electrolysis reaction: 2 AlOF3-2 + C → 2 Al + CO2 + F-
Where would the aluminum form?

Accepted Answer

A) cathode 
B) anode 
C) in solution 
D) Aluminum formation does not happen because electrons do not flow in above reaction. 
E) none of the above

Question 7

How many electrons are gained or lost in the following half-reaction? Cl2 → 2 Cl-

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 8

-Which of the above illustrations shows a basic aqueous solution?

Accepted Answer

A) A 
B) B 
C) C 
D) All of the above are neutral solutions. 
E) none of the above

Question 9

What is the hydroxide ion concentration in an aqueous solution when the hydronium ion concentration equals 1 × $$10 ^ { - 10 }$$ moles per liter?

Accepted Answer

A) The concentration of hydroxide ions is 1 × $10 ^ { - 10 }$ moles per liter. 
B) The concentration of hydroxide ions is 1 × $10 ^ { - 4 }$ moles per liter. 
C) The concentration of hydroxide ions is 1 × $10 ^ { - 2 }$ moles per liter. 
D) The concentration of hydroxide ions is 1 × $10 ^ { - 6 }$

Question 10

In a battery,if the following oxidation-reduction reactions takes place normally: Mn2O3 + ZnO → 2 MnO2 + Zn
What reaction would be taking place if you were charging the battery?

Accepted Answer

A) 2 MnO2 + Zn → Mn2O3 + ZnO 
B) ZnO → Zn 
C) Mn2O3 → MnO2 
D) all of the above 
E) none of the above

Question 11

What would the concentration of H3O+ be if the concentration of OH- was 1 × 10-11M? [H3O+] × [OH-] = Kw = 1 × 10-14

Accepted Answer

A) 1 × 10-3 
B) 1 × 103 
C) 1 × 1014 
D) 1 × 1012 
E) 1 × 10-6

Question 12

Cutting back on the pollutants that cause acid rain is one solution to the problem of acidified lakes.Suggest another.

Accepted Answer

A) stop using NaCl to salt the roads in the winter 
B) add a neutralizing substance such as limestone 
C) add ammonium ions to the lakes 
D) add chlorine and filter the water to remove any acidity in the lake

Question 13

Which of the following reactions illustrates an amphoteric compound?

Accepted Answer

A) 2 HF ⇌ H2F+ + F- 
B) NaOH + HBr ⇌ NaBr + H2O 
C) 2 H2 + O2 ⇌ 2 H2O 
D) All are amphoteric. 
E) none of the above

Question 14

What best describes what happens when an acid such as HCl is mixed with water?

Accepted Answer

A) The proton chemically bonded to the chlorine is transferred to a water molecule and forms a chloride ion and a hydronium ion. 
B) A proton from the chlorine nucleus is ejected and captured by a water molecule to form a negatively charged HCl and a new hydronium ion. 
C) A hydroxide ion from the water is transferred to the HCl molecule to form a proton and hydronium ion. 
D) HCl is not an acid. 
E) none of the above

Question 15

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 16

What do the brackets in the following equation represent? [H3O+] × [OH-] = Kw

Accepted Answer

A) The brackets mean the molarity of the compound inside them. 
B) The molecule inside does not react with the other molecules in brackets. 
C) The molecule in brackets is undergoing hydrogen bonding with the other molecule in brackets. 
D) The first molecule in brackets is an acid and it reacts with the second molecule in brackets,which is a base. 
E) none of the above

Question 17

-Which of the above illustrations shows a neutral aqueous solution?

Accepted Answer

A) A 
B) B 
C) C 
D) All of the above are neutral solutions. 
E) none of the above

Question 18

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 19

When a hydronium ion concentration equals 1 × $10 ^ { - 4 }$ moles per liter,what is the pH of the solution? Is the solution acidic or basic?

Accepted Answer

A) The pH is of this solution is 4 and it is acidic. 
B) The pH is of this solution is 8 and it is basic. 
C) The pH is of this solution is 6 and it is acidic. 
D) The pH is of this solution is 10 and it is basic.

Question 20

Which of the following species is undergoing reduction? 2 CuBr → 2Cu + Br2

Accepted Answer

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

Exam 18: Two Classes of Chemical Reactions

What is one of the drawbacks to using fuel cells?

Which of the half-reactions below would be complementary and balance the following half-reaction? Zn⁺² → Zn

How would connecting iron with a wire to a piece of metal like copper,which undergoes reduction very easily,affect the rate at which the iron corrodes?

How might you tell whether or not your toothpaste contained either calcium carbonate,CaC $\mathrm { O } _ { 3 }$ ,or baking soda,NaHC $\mathrm { O } _ { 3 }$ ,without looking at the ingredients label?

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

For the following electrolysis reaction: 2 AlOF₃^-2 + C → 2 Al + CO₂ + F^- Where would the aluminum form?

How many electrons are gained or lost in the following half-reaction? Cl₂ → 2 Cl^-

-Which of the above illustrations shows a basic aqueous solution?

What is the hydroxide ion concentration in an aqueous solution when the hydronium ion concentration equals 1 × $10 ^ { - 10 }$ moles per liter?

In a battery,if the following oxidation-reduction reactions takes place normally: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What reaction would be taking place if you were charging the battery?

What would the concentration of H₃O⁺ be if the concentration of OH^- was 1 × 10^-11M? [H₃O⁺] × [OH^-] = K_w= 1 × 10^-14

Cutting back on the pollutants that cause acid rain is one solution to the problem of acidified lakes.Suggest another.

Which of the following reactions illustrates an amphoteric compound?

What best describes what happens when an acid such as HCl is mixed with water?

What is oxidation?

What do the brackets in the following equation represent? [H₃O⁺] × [OH^-] = K_w

-Which of the above illustrations shows a neutral aqueous solution?

Suggest why people once washed their hands with ashes.

When a hydronium ion concentration equals 1 × $10 ^ { - 4 }$ moles per liter,what is the pH of the solution? Is the solution acidic or basic?

Which of the following species is undergoing reduction? 2 CuBr → 2Cu + Br₂

Exam 18: Two Classes of Chemical Reactions

What is one of the drawbacks to using fuel cells?

Which of the half-reactions below would be complementary and balance the following half-reaction? Zn+2 → Zn

How would connecting iron with a wire to a piece of metal like copper,which undergoes reduction very easily,affect the rate at which the iron corrodes?

How might you tell whether or not your toothpaste contained either calcium carbonate,CaC O3\mathrm { O } _ { 3 }O3​ ,or baking soda,NaHC O3\mathrm { O } _ { 3 }O3​ ,without looking at the ingredients label?

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

For the following electrolysis reaction: 2 AlOF3-2 + C → 2 Al + CO2 + F- Where would the aluminum form?

How many electrons are gained or lost in the following half-reaction? Cl2 → 2 Cl-

-Which of the above illustrations shows a basic aqueous solution?

What is the hydroxide ion concentration in an aqueous solution when the hydronium ion concentration equals 1 × 10−1010 ^ { - 10 }10−10 moles per liter?

In a battery,if the following oxidation-reduction reactions takes place normally: Mn2O3 + ZnO → 2 MnO2 + Zn What reaction would be taking place if you were charging the battery?

What would the concentration of H3O+ be if the concentration of OH- was 1 × 10-11M? [H3O+] × [OH-] = Kw = 1 × 10-14

Cutting back on the pollutants that cause acid rain is one solution to the problem of acidified lakes.Suggest another.

Which of the following reactions illustrates an amphoteric compound?

What best describes what happens when an acid such as HCl is mixed with water?

What is oxidation?

What do the brackets in the following equation represent? [H3O+] × [OH-] = Kw

-Which of the above illustrations shows a neutral aqueous solution?

Suggest why people once washed their hands with ashes.

When a hydronium ion concentration equals 1 × 10−410 ^ { - 4 }10−4 moles per liter,what is the pH of the solution? Is the solution acidic or basic?

Which of the following species is undergoing reduction? 2 CuBr → 2Cu + Br2

Which of the half-reactions below would be complementary and balance the following half-reaction? Zn⁺² → Zn

How might you tell whether or not your toothpaste contained either calcium carbonate,CaC $\mathrm { O } _ { 3 }$ ,or baking soda,NaHC $\mathrm { O } _ { 3 }$ ,without looking at the ingredients label?

For the following electrolysis reaction: 2 AlOF₃^-2 + C → 2 Al + CO₂ + F^- Where would the aluminum form?

How many electrons are gained or lost in the following half-reaction? Cl₂ → 2 Cl^-

What is the hydroxide ion concentration in an aqueous solution when the hydronium ion concentration equals 1 × $10 ^ { - 10 }$ moles per liter?

In a battery,if the following oxidation-reduction reactions takes place normally: Mn₂O₃ + ZnO → 2 MnO₂ + Zn What reaction would be taking place if you were charging the battery?

What would the concentration of H₃O⁺ be if the concentration of OH^- was 1 × 10^-11M? [H₃O⁺] × [OH^-] = K_w= 1 × 10^-14

What do the brackets in the following equation represent? [H₃O⁺] × [OH^-] = K_w

When a hydronium ion concentration equals 1 × $10 ^ { - 4 }$ moles per liter,what is the pH of the solution? Is the solution acidic or basic?

Which of the following species is undergoing reduction? 2 CuBr → 2Cu + Br₂