Question 1

What is the main factor that directly determines the pH of any buffer?

Accepted Answer

The pK_a of

Question 2

Use the following to answer questions 55-58:  
-The galvanic cell shown above uses the half-cells Pb2+/Pb and Zn2+/Zn,and a salt bridge containing KCl(aq).The voltmeter gives a positive voltage reading.The electrode B could be inert platinum metal or zinc.

Accepted Answer

A) True 
 B)False

Question 3

Choose the effective pH range of an aniline/anilinium chloride buffer .
The value of the Kb for aniline is 4.3 * 10-10.

Accepted Answer

A)  3.6-5.6 
B)  8.4-10.4 
C)  1.1-3.1 
D)  5.1-7.1 
E)  10.1-12.1 
A)  3.6-5.6 
B)  8.4-10.4 
C)  1.1-3.1 
D)  5.1-7.1 
E)  10.1-12.1

Question 4

Write the autoprotolysis reaction for liquid ammonia.

Accepted Answer

2NH₃(l).N

Question 5

If pKa1 and pKa2 for H2CO3 are 6.37 and 10.25, respectively,Calculate the equilibrium constant for the reaction below:
H2CO3(aq)+ 2H2O(l)$\Leftrightarrow$2H3O+(aq)+ CO32-(aq)

Accepted Answer

A)  4.1 * 10-11  
B)  4.3 * 10-7  
C)  5.6 * 10-11  
D)  2.3 * 10-8  
E)  2.4 * 10-17  
A)  4.1 * 10-11  
B)  4.3 * 10-7  
C)  5.6 * 10-11  
D)  2.3 * 10-8  
E)  2.4 * 10-17

Question 6

If a small amount of a strong base is added to buffer made up of a weak acid, HA,And the sodium salt of its conjugate base,NaA,The pH of the buffer solution does not change appreciably because

Accepted Answer

A)  the Ka of HA is changed. 
B)  No reaction occurs. 
C)  the strong base reacts with A- to give HA, which is a weak acid. 
D)  the strong base reacts with HA to give AOH and H+. 
E)  the strong base reacts with HA to give A-, which is a weak base. 
A)  the Ka of HA is changed. 
B)  No reaction occurs. 
C)  the strong base reacts with A- to give HA, which is a weak acid. 
D)  the strong base reacts with HA to give AOH and H+. 
E)  the strong base reacts with HA to give A-, which is a weak base.

Question 7

What is the pH of an aqueous solution that is 0.60 (CH3)3N (Kb = 6.5 * 10-5) and 0.95 M (CH3)3NHCl?

Accepted Answer

A)  4.39 
B)  10.01 
C)  3.99 
D)  9.81 
E)  9.61 
A)  4.39 
B)  10.01 
C)  3.99 
D)  9.81 
E)  9.61

Question 8

Use the following diagram of a cell to answer questions 59-64:  
-In the cell shown above, A is a standard Zn2+/Zn electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is -0.76 V,
Which half-reaction occurs in the left-hand cell compartment?

Accepted Answer

A)  Zn2+(aq) + 2e- $\rightarrow$ Zn(s) 
B)  Zn(s) $\rightarrow$Zn2+(aq) + 2e-  
A)  Zn2+(aq) + 2e- $\rightarrow$ Zn(s) 
B)  Zn(s) $\rightarrow$Zn2+(aq) + 2e-

Question 9

In the Daniell cell,the anode is zinc metal and the cathode is copper metal.When the cell operates,the anode gets smaller and the cathode gets larger.

Accepted Answer

A) True 
 B)False

Question 10

Consider the following cell at standard conditions:
Zn(s)|Zn2+(aq)M Fe2+(aq)|Fe(s)
Calculate the value of $\Delta$Gr$\omicron$for the reaction that occurs when current is drawn from this cell.

Accepted Answer

A)  -62 kJ.mol-1  
B)  -230 kJ.mol-1  
C)  +62 kJ.mol-1  
D)  +230 kJ.mol-1  
E)  -31 kJ.mol-1  
A)  -62 kJ.mol-1  
B)  -230 kJ.mol-1  
C)  +62 kJ.mol-1  
D)  +230 kJ.mol-1  
E)  -31 kJ.mol-1

Question 11

If the standard potential for Cu2+(aq)/Cu+(aq) is 0.15 V and the standard potential for Cu2+(aq)/Cu(s)Is 0.34 V,Calculate the standard potential for
Cu+(aq)+ e- $\rightarrow$ Cu(s).

Accepted Answer

A)  +0.32 V 
B)  +0.64 V 
C)  +0.53 V 
D)  +0.83 V 
E)  +0.49 V 
A)  +0.32 V 
B)  +0.64 V 
C)  +0.53 V 
D)  +0.83 V 
E)  +0.49 V

Question 12

A buffer solution contains 0.0200 M acetic acid and 0.0200 M sodium acetate.What is the pH after 2.0 mmol of NaOH are added to 1.00 L of this buffer? pKa = 4.75 for acetic acid.

Accepted Answer

A)  4.75 
B)  4.70 
C)  4.80 
D)  4.84 
E)  4.66 
A)  4.75 
B)  4.70 
C)  4.80 
D)  4.84 
E)  4.66

Question 13

If the molar solubility of the compound M2A3 is 7.0 * 10-6 M, what is the Ksp for this compound?

Accepted Answer

A)  1.7 * 10-26 
B)  1.8 * 10-24 
C)  2.9 * 10-10 
D)  3.5 * 10-5 
A)  1.7 * 10-26 
B)  1.8 * 10-24 
C)  2.9 * 10-10 
D)  3.5 * 10-5

Question 14

Which of the following aqueous solutions gives a pH greater than 7?

Accepted Answer

A)  10-8 M NH4Cl 
B)  None of the solutions gives a pH greater than 7. 
C)  10-8 M CH3COOH 
D)  10-8 M HCl 
E)  10-8 M HCOOH 
A)  10-8 M NH4Cl 
B)  None of the solutions gives a pH greater than 7. 
C)  10-8 M CH3COOH 
D)  10-8 M HCl 
E)  10-8 M HCOOH

Question 15

The pH of 0.010 M aniline(aq) is 8.32.What is the percentage aniline protonated?

Accepted Answer

A)  2.1% 
B)  0.69% 
C)  0.021% 
D)  0.12% 
E)  0.21% 
A)  2.1% 
B)  0.69% 
C)  0.021% 
D)  0.12% 
E)  0.21%

Question 16

How many seconds are required to produce 4.99 mg of chromium metal from an acidic solution of potassium dichromate,using a current of 0.234 A?

Accepted Answer

The answer of How many seconds are required to produce...

Question 17

For the following acids, which has the highest pKa?

Accepted Answer

A)  HIO 
B)  HClO3  
C)  HClO 
D)  HBrO 
E)  HClO4  
A)  HIO 
B)  HClO3  
C)  HClO 
D)  HBrO 
E)  HClO4

Question 18

Use the following diagram of a cell to answer questions 59-64:  
-In the cell shown above, A is a standard Ag+/Ag electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is +0.80 V,
What is the equation for the cell reaction?

Accepted Answer

A)  Ag(s) + H+(aq) $\rightarrow$ Ag+(aq) + ½H2(g) 
B)  Ag+(aq) + ½H2(g) $\rightarrow$Ag(s) + H+(aq) 
A)  Ag(s) + H+(aq) $\rightarrow$ Ag+(aq) + ½H2(g) 
B)  Ag+(aq) + ½H2(g) $\rightarrow$Ag(s) + H+(aq)

Question 19

Consider the titration of 50.0 mL of 0.0200 M HClO(aq)with 0.100 M NaOH(aq).What is the formula of the main species in the solution after the addition of 10.0 mL of base?

Accepted Answer

The answer of Consider the titration of 50.0 mL of...

Question 20

Use the following diagram of a cell to answer questions 59-64:  
-In the cell shown above, A is a standard Zn2+/Zn electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is-0.76 V,
What is the equation for the cell reaction?

Accepted Answer

A)  Zn2+(aq) + H2(g) $\rightarrow$ Zn(s) + 2H+(aq) 
B)  Zn(s) + 2H+(aq) $\rightarrow$ Zn2+(aq) + H2(g) 
A)  Zn2+(aq) + H2(g) $\rightarrow$ Zn(s) + 2H+(aq) 
B)  Zn(s) + 2H+(aq) $\rightarrow$ Zn2+(aq) + H2(g)

What is the main factor that directly determines the pH of any buffer?

Use the following to answer questions 55-58: -The galvanic cell shown above uses the half-cells Pb²⁺/Pb and Zn²⁺/Zn,and a salt bridge containing KCl(aq).The voltmeter gives a positive voltage reading.The electrode B could be inert platinum metal or zinc.

Choose the effective pH range of an aniline/anilinium chloride buffer . The value of the K_b for aniline is 4.3 * 10^-¹⁰.

Write the autoprotolysis reaction for liquid ammonia.

If pK_a1 and pK_a2 for H₂CO₃ are 6.37 and 10.25, respectively,Calculate the equilibrium constant for the reaction below: H₂CO₃(aq)+ 2H₂O(l) $\Leftrightarrow$ 2H₃O⁺(aq)+ CO₃²^-(aq)

If a small amount of a strong base is added to buffer made up of a weak acid, HA,And the sodium salt of its conjugate base,NaA,The pH of the buffer solution does not change appreciably because

What is the pH of an aqueous solution that is 0.60 (CH₃)₃N (K_b = 6.5 * 10^-⁵) and 0.95 M (CH₃)₃NHCl?

Use the following diagram of a cell to answer questions 59-64: -In the cell shown above, A is a standard Zn²⁺/Zn electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is -0.76 V, Which half-reaction occurs in the left-hand cell compartment?

In the Daniell cell,the anode is zinc metal and the cathode is copper metal.When the cell operates,the anode gets smaller and the cathode gets larger.

Consider the following cell at standard conditions: Zn(s)|Zn²⁺(aq)M Fe²⁺(aq)|Fe(s) Calculate the value of $\Delta$ G_r^$\omicron$for the reaction that occurs when current is drawn from this cell.

If the standard potential for Cu²⁺(aq)/Cu⁺(aq) is 0.15 V and the standard potential for Cu²⁺(aq)/Cu(s)Is 0.34 V,Calculate the standard potential for Cu⁺(aq)+ e^- $\rightarrow$ Cu(s).

A buffer solution contains 0.0200 M acetic acid and 0.0200 M sodium acetate.What is the pH after 2.0 mmol of NaOH are added to 1.00 L of this buffer? pK_a = 4.75 for acetic acid.

If the molar solubility of the compound M₂A₃ is 7.0 * 10^-⁶ M, what is the K_sp for this compound?

Which of the following aqueous solutions gives a pH greater than 7?

The pH of 0.010 M aniline(aq) is 8.32.What is the percentage aniline protonated?

How many seconds are required to produce 4.99 mg of chromium metal from an acidic solution of potassium dichromate,using a current of 0.234 A?

For the following acids, which has the highest pK_a?

Use the following diagram of a cell to answer questions 59-64: -In the cell shown above, A is a standard Ag⁺/Ag electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is +0.80 V, What is the equation for the cell reaction?

Consider the titration of 50.0 mL of 0.0200 M HClO(aq)with 0.100 M NaOH(aq).What is the formula of the main species in the solution after the addition of 10.0 mL of base?

Use the following diagram of a cell to answer questions 59-64: -In the cell shown above, A is a standard Zn²⁺/Zn electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is-0.76 V, What is the equation for the cell reaction?

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Exam 6: Reactions

What is the main factor that directly determines the pH of any buffer?

Use the following to answer questions 55-58: -The galvanic cell shown above uses the half-cells Pb2+/Pb and Zn2+/Zn,and a salt bridge containing KCl(aq).The voltmeter gives a positive voltage reading.The electrode B could be inert platinum metal or zinc.

Choose the effective pH range of an aniline/anilinium chloride buffer . The value of the Kb for aniline is 4.3 * 10-10.

Write the autoprotolysis reaction for liquid ammonia.

If pKa1 and pKa2 for H2CO3 are 6.37 and 10.25, respectively,Calculate the equilibrium constant for the reaction below: H2CO3(aq)+ 2H2O(l) ⇔\Leftrightarrow⇔ 2H3O+(aq)+ CO32-(aq)

If a small amount of a strong base is added to buffer made up of a weak acid, HA,And the sodium salt of its conjugate base,NaA,The pH of the buffer solution does not change appreciably because

What is the pH of an aqueous solution that is 0.60 (CH3)3N (Kb = 6.5 * 10-5) and 0.95 M (CH3)3NHCl?

Use the following diagram of a cell to answer questions 59-64: -In the cell shown above, A is a standard Zn2+/Zn electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is -0.76 V, Which half-reaction occurs in the left-hand cell compartment?

In the Daniell cell,the anode is zinc metal and the cathode is copper metal.When the cell operates,the anode gets smaller and the cathode gets larger.

Consider the following cell at standard conditions: Zn(s)|Zn2+(aq)M Fe2+(aq)|Fe(s) Calculate the value of Δ\DeltaΔ Gr ο\omicronο for the reaction that occurs when current is drawn from this cell.

If the standard potential for Cu2+(aq)/Cu+(aq) is 0.15 V and the standard potential for Cu2+(aq)/Cu(s)Is 0.34 V,Calculate the standard potential for Cu+(aq)+ e- →\rightarrow→ Cu(s).

A buffer solution contains 0.0200 M acetic acid and 0.0200 M sodium acetate.What is the pH after 2.0 mmol of NaOH are added to 1.00 L of this buffer? pKa = 4.75 for acetic acid.

If the molar solubility of the compound M2A3 is 7.0 * 10-6 M, what is the Ksp for this compound?

Which of the following aqueous solutions gives a pH greater than 7?

The pH of 0.010 M aniline(aq) is 8.32.What is the percentage aniline protonated?

How many seconds are required to produce 4.99 mg of chromium metal from an acidic solution of potassium dichromate,using a current of 0.234 A?

For the following acids, which has the highest pKa?

Use the following diagram of a cell to answer questions 59-64: -In the cell shown above, A is a standard Ag+/Ag electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is +0.80 V, What is the equation for the cell reaction?

Consider the titration of 50.0 mL of 0.0200 M HClO(aq)with 0.100 M NaOH(aq).What is the formula of the main species in the solution after the addition of 10.0 mL of base?

Use the following diagram of a cell to answer questions 59-64: -In the cell shown above, A is a standard Zn2+/Zn electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is-0.76 V, What is the equation for the cell reaction?

Atoms

Molecules

States of Matter

Thermodynamics

Equilibrium

Kinetics

The Main-Group Elements

The D-Block Elements

Nuclear Chemistry

Organic Chemistry

Filters

Use the following to answer questions 55-58: -The galvanic cell shown above uses the half-cells Pb²⁺/Pb and Zn²⁺/Zn,and a salt bridge containing KCl(aq).The voltmeter gives a positive voltage reading.The electrode B could be inert platinum metal or zinc.

Choose the effective pH range of an aniline/anilinium chloride buffer . The value of the K_b for aniline is 4.3 * 10^-¹⁰.

If pK_a1 and pK_a2 for H₂CO₃ are 6.37 and 10.25, respectively,Calculate the equilibrium constant for the reaction below: H₂CO₃(aq)+ 2H₂O(l) $\Leftrightarrow$ 2H₃O⁺(aq)+ CO₃²^-(aq)

What is the pH of an aqueous solution that is 0.60 (CH₃)₃N (K_b = 6.5 * 10^-⁵) and 0.95 M (CH₃)₃NHCl?

Use the following diagram of a cell to answer questions 59-64: -In the cell shown above, A is a standard Zn²⁺/Zn electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is -0.76 V, Which half-reaction occurs in the left-hand cell compartment?

Consider the following cell at standard conditions: Zn(s)|Zn²⁺(aq)M Fe²⁺(aq)|Fe(s) Calculate the value of $\Delta$ G_r^$\omicron$for the reaction that occurs when current is drawn from this cell.

If the standard potential for Cu²⁺(aq)/Cu⁺(aq) is 0.15 V and the standard potential for Cu²⁺(aq)/Cu(s)Is 0.34 V,Calculate the standard potential for Cu⁺(aq)+ e^- $\rightarrow$ Cu(s).

A buffer solution contains 0.0200 M acetic acid and 0.0200 M sodium acetate.What is the pH after 2.0 mmol of NaOH are added to 1.00 L of this buffer? pK_a = 4.75 for acetic acid.

If the molar solubility of the compound M₂A₃ is 7.0 * 10^-⁶ M, what is the K_sp for this compound?

For the following acids, which has the highest pK_a?

Use the following diagram of a cell to answer questions 59-64: -In the cell shown above, A is a standard Ag⁺/Ag electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is +0.80 V, What is the equation for the cell reaction?

Use the following diagram of a cell to answer questions 59-64: -In the cell shown above, A is a standard Zn²⁺/Zn electrode connected to a standard hydrogen electrode (SHE).If the voltmeter reading is-0.76 V, What is the equation for the cell reaction?