Question 1

For NH3, pKb = 4.74.What is the pH of an aqueous buffer solution that is 0.050 M NH3(aq)And 0.20 M NH4Cl(aq)?

Accepted Answer

A)  9.86 
B)  5.34 
C)  9.26 
D)  8.66 
E)  4.14 
A)  9.86 
B)  5.34 
C)  9.26 
D)  8.66 
E)  4.14

Question 2

In a working electrochemical cell (+ cell voltage),the electrons flow from the anode through the external circuit to the cathode.

Accepted Answer

A) True 
 B)False

Question 3

The following compounds are available as 0.10 M aqueous solutions. $$\begin{array} { | l | l | l | } 
\hline \text { A) pyridine } & \text { B) } \mathrm { LiClO } _ { 4 } & \text { C) } \mathrm { HClO } _ { 4 } \
\hline \text { D) } \mathrm { HClO } _ { 2 } & \text { E) } \mathrm { NaOH } & \text { F) phenol } \
\hline \text { G) triethylamine } & \text { H) } \mathrm { HClO } & \text { I) } \mathrm { NH } _ { 3 } \
\hline
\end{array}$$ 
Which two solutions could be used to prepare a buffer with a pH of ~ 2.5?

Accepted Answer

The answer of The following compounds are available as 0.10...

Question 4

For a 0.10 M solution of a weak acid, HA,With pKa = 10,Which of the following is true?

Accepted Answer

A)  [HA] $\cong$ 0 
B)  [HA] = [A-] 
C)  [HA] = [H3O+] 
D)  [HA] = Ka  
E)  [HA] $\neq$ [H3O+] 
A)  [HA] $\cong$ 0 
B)  [HA] = [A-] 
C)  [HA] = [H3O+] 
D)  [HA] = Ka  
E)  [HA] $\neq$ [H3O+]

Question 5

Which of the following is the strongest oxidizing agent?

Accepted Answer

A)  O3 
B)  MnO4- 
C)  Cr2O72- 
D)  Cl2 
A)  O3 
B)  MnO4- 
C)  Cr2O72- 
D)  Cl2

Question 6

For the titration of 50.0 mL of 0.020 M aqueous salicylic acid with 0.020 M KOH(aq), calculate the pH after the addition of 55.0 mL of KOH(aq).For salycylic acid,PKa = 2.97.

Accepted Answer

A)  10.98 
B)  7.00 
C)  11.26 
D)  12.02 
E)  12.30 
A)  10.98 
B)  7.00 
C)  11.26 
D)  12.02 
E)  12.30

Question 7

Given: N2H5+(aq) $\rarr$ N2(g).
How many electrons appear in the balanced half-reaction?

Accepted Answer

A)  6 
B)  2 
C)  1 
D)  4 
E)  5 
A)  6 
B)  2 
C)  1 
D)  4 
E)  5

Question 8

The following compounds are available as 0.10 M aqueous solutions. $$\begin{array} { | l | l | l | } 
\hline \text { A) } \mathrm { HCl } & \text { B) aniline } & \text { C) } \mathrm { HCN } \
\hline \text { D) } \mathrm { KOH } & \text { E) methylamine } & \text { F) } \mathrm { HClO } \
\hline \text { G) } \mathrm { HClO } _ { 2 } & \text { H) } \mathrm { NaClO } _ { 2 } & \text { I) triethylamine } \
\hline
\end{array}$$ 
Pick two solutions that could be used to prepare a buffer with a pH of ~ 10.8.More than one answer may be possible.

Accepted Answer

The answer of The following compounds are available as 0.10...

Question 9

What is the proper cell diagram for the reaction
2AgCl(s)+ H2(g)$\rightarrow$2Ag(s)+ 2H+(aq)+ 2Cl-(aq)

Accepted Answer

Question 10

Calculate the [H+] in an aqueous solution that is 0.0755 M HF and 0.100 M NaF .The value of Ka for HF is 3.5 * 10-4.

Accepted Answer

A)  4.6 * 10-4 M 
B)  2.6  10-4 M 
C)  3.5*10-4 M 
D)  0.176 M 
E)  0.0755 M 
A)  4.6 * 10-4 M 
B)  2.6  10-4 M 
C)  3.5*10-4 M 
D)  0.176 M 
E)  0.0755 M

Question 11

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 electrode is negative?

Accepted Answer

The answer of Use the following diagram of a cell...

Question 12

What is the pH at the half-stoichiometric point for the titration of 0.88 M HNO2(aq) with 0.10 M KOH(aq)? For HNO2,Ka = 4.3 * 10-4.

Accepted Answer

A)  3.37 
B)  2.01 
C)  1.86 
D)  7.00 
E)  1.71 
A)  3.37 
B)  2.01 
C)  1.86 
D)  7.00 
E)  1.71

Question 13

You have available the following reagents as 0.10 M aqueous solutions:NaOH,HCl,Phenol (pKa = 9.89),Aniline (pKb = 9.37),HNO2 (pKa = 3.37),CH3NH2 (pKb = 3.44).Which two reagents would you use to make a buffer with a pH of 10.5?

Accepted Answer

A)  HCl and CH3NH2 
B)  HCl and aniline 
C)  NaOH and phenol 
D)  NaOH and HNO2 
E)  HCl and phenol 
A)  HCl and CH3NH2 
B)  HCl and aniline 
C)  NaOH and phenol 
D)  NaOH and HNO2 
E)  HCl and phenol

Question 14

A certain weak acid has a Ka of 2.0 *10-5.What is the equilibrium constant for the reaction of this acid with a strong base?

Accepted Answer

2.0 * 10<s

Question 15

A 0.0010 M solution of a weak acid, HA,With Ka = 2 * 10-10 produces [H3O+] -6 M.Which of the following equations can be used to determine [H3O+]?

Accepted Answer

A)  The acid is so weak that the pH is about 7. 
B)  [H3O+]2 + Ka [H3O+] - [HA]initialKa = 0 
C)  [H3O+] = (Kw + Ka[HA]initial)½ 
D)  [H3O+] = [HA]initial  
E)  [H3O+] = (Ka[HA]initial)½ 
A)  The acid is so weak that the pH is about 7. 
B)  [H3O+]2 + Ka [H3O+] - [HA]initialKa = 0 
C)  [H3O+] = (Kw + Ka[HA]initial)½ 
D)  [H3O+] = [HA]initial  
E)  [H3O+] = (Ka[HA]initial)½

Question 16

Calculate the equilibrium constant for the reaction that occurs when perchloric acid is added to the buffer B(aq)/BHCl(aq).The Kb of B is 3.4 * 10-5.

Accepted Answer

3.4 * 10<s

Question 17

In order to convert hydrazine, N2H4,To nitric acid,

Accepted Answer

A)  an oxidizing agent is required. 
B)  a reducing agent is required. 
A)  an oxidizing agent is required. 
B)  a reducing agent is required.

Question 18

For a solution labeled "0.10 M H3PO4(aq),"

Accepted Answer

A)  [H2PO4?] is greater than 0.10 M. 
B)  [H+] = 0.30 M. 
C)  [PO43-] = 0.10 M. 
D)  [H+] = 0.10 M. 
E)  [H+] is less than 0.10 M. 
A)  [H2PO4?] is greater than 0.10 M. 
B)  [H+] = 0.30 M. 
C)  [PO43-] = 0.10 M. 
D)  [H+] = 0.10 M. 
E)  [H+] is less than 0.10 M.

Question 19

The solubility of all except which the following compounds increases as the pH of the solution decreases?

Accepted Answer

A)  CaF2 
B)  Na2CO3 
C)  PbSO3 
D)  KClO4 
E)  CuS 
A)  CaF2 
B)  Na2CO3 
C)  PbSO3 
D)  KClO4 
E)  CuS

Question 20

Consider the titration of 10.0 mL of 0.100 M (CH3)3N(aq)
with 0.100 M HClO4(aq).What is the formula of the main species in the solution after the addition of 10.0 mL of acid?

Accepted Answer

For NH₃, pK_b = 4.74.What is the pH of an aqueous buffer solution that is 0.050 M NH₃(aq)And 0.20 M NH₄Cl(aq)?

In a working electrochemical cell (+ cell voltage),the electrons flow from the anode through the external circuit to the cathode.

The following compounds are available as 0.10 M aqueous solutions. A) pyridine B) C) D) E) F) phenol G) triethylamine H) I) Which two solutions could be used to prepare a buffer with a pH of ~ 2.5?

For a 0.10 M solution of a weak acid, HA,With pK_a = 10,Which of the following is true?

Which of the following is the strongest oxidizing agent?

For the titration of 50.0 mL of 0.020 M aqueous salicylic acid with 0.020 M KOH(aq), calculate the pH after the addition of 55.0 mL of KOH(aq).For salycylic acid,PK_a = 2.97.

Given: N₂H₅⁺(aq) $\rarr$ N₂(g). How many electrons appear in the balanced half-reaction?

The following compounds are available as 0.10 M aqueous solutions. A) B) aniline C) D) E) methylamine F) G) H) I) triethylamine Pick two solutions that could be used to prepare a buffer with a pH of ~ 10.8.More than one answer may be possible.

What is the proper cell diagram for the reaction 2AgCl(s)+ H₂(g) $\rightarrow$ 2Ag(s)+ 2H⁺(aq)+ 2Cl^-(aq)

Calculate the [H⁺] in an aqueous solution that is 0.0755 M HF and 0.100 M NaF .The value of K_a for HF is 3.5 * 10^-⁴.

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 electrode is negative?

What is the pH at the half-stoichiometric point for the titration of 0.88 M HNO₂(aq) with 0.10 M KOH(aq)? For HNO₂,K_a = 4.3 * 10^-⁴.

You have available the following reagents as 0.10 M aqueous solutions:NaOH,HCl,Phenol (pK_a = 9.89),Aniline (pK_b = 9.37),HNO₂ (pK_a = 3.37),CH₃NH₂ (pK_b = 3.44).Which two reagents would you use to make a buffer with a pH of 10.5?

A certain weak acid has a K_a of 2.0 *10^-⁵.What is the equilibrium constant for the reaction of this acid with a strong base?

A 0.0010 M solution of a weak acid, HA,With K_a = 2 * 10^-¹⁰ produces [H₃O⁺] < 10^-⁶ M.Which of the following equations can be used to determine [H₃O⁺]?

Calculate the equilibrium constant for the reaction that occurs when perchloric acid is added to the buffer B(aq)/BHCl(aq).The K_b of B is 3.4 * 10^-⁵.

In order to convert hydrazine, N₂H₄,To nitric acid,

For a solution labeled "0.10 M H₃PO₄(aq),"

The solubility of all except which the following compounds increases as the pH of the solution decreases?

Consider the titration of 10.0 mL of 0.100 M (CH₃)₃N(aq) with 0.100 M HClO₄(aq).What is the formula of the main species in the solution after the addition of 10.0 mL of acid?

Atoms

Molecules

States of Matter

Thermodynamics

Equilibrium

Kinetics

The Main-Group Elements

The D-Block Elements

Nuclear Chemistry

Organic Chemistry

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Exam 6: Reactions

For NH3, pKb = 4.74.What is the pH of an aqueous buffer solution that is 0.050 M NH3(aq)And 0.20 M NH4Cl(aq)?

In a working electrochemical cell (+ cell voltage),the electrons flow from the anode through the external circuit to the cathode.

The following compounds are available as 0.10 M aqueous solutions. A) pyridine B) C) D) E) F) phenol G) triethylamine H) I) Which two solutions could be used to prepare a buffer with a pH of ~ 2.5?

For a 0.10 M solution of a weak acid, HA,With pKa = 10,Which of the following is true?

Which of the following is the strongest oxidizing agent?

For the titration of 50.0 mL of 0.020 M aqueous salicylic acid with 0.020 M KOH(aq), calculate the pH after the addition of 55.0 mL of KOH(aq).For salycylic acid,PKa = 2.97.

Given: N2H5+(aq) →\rarr→ N2(g). How many electrons appear in the balanced half-reaction?

The following compounds are available as 0.10 M aqueous solutions. A) B) aniline C) D) E) methylamine F) G) H) I) triethylamine Pick two solutions that could be used to prepare a buffer with a pH of ~ 10.8.More than one answer may be possible.

What is the proper cell diagram for the reaction 2AgCl(s)+ H2(g) →\rightarrow→ 2Ag(s)+ 2H+(aq)+ 2Cl-(aq)

Calculate the [H+] in an aqueous solution that is 0.0755 M HF and 0.100 M NaF .The value of Ka for HF is 3.5 * 10-4.

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 electrode is negative?

What is the pH at the half-stoichiometric point for the titration of 0.88 M HNO2(aq) with 0.10 M KOH(aq)? For HNO2,Ka = 4.3 * 10-4.

You have available the following reagents as 0.10 M aqueous solutions:NaOH,HCl,Phenol (pKa = 9.89),Aniline (pKb = 9.37),HNO2 (pKa = 3.37),CH3NH2 (pKb = 3.44).Which two reagents would you use to make a buffer with a pH of 10.5?

A certain weak acid has a Ka of 2.0 *10-5.What is the equilibrium constant for the reaction of this acid with a strong base?

A 0.0010 M solution of a weak acid, HA,With Ka = 2 * 10-10 produces [H3O+] < 10-6 M.Which of the following equations can be used to determine [H3O+]?

Calculate the equilibrium constant for the reaction that occurs when perchloric acid is added to the buffer B(aq)/BHCl(aq).The Kb of B is 3.4 * 10-5.

In order to convert hydrazine, N2H4,To nitric acid,

For a solution labeled "0.10 M H3PO4(aq),"

The solubility of all except which the following compounds increases as the pH of the solution decreases?

Consider the titration of 10.0 mL of 0.100 M (CH3)3N(aq) with 0.100 M HClO4(aq).What is the formula of the main species in the solution after the addition of 10.0 mL of acid?

Atoms

Molecules

States of Matter

Thermodynamics

Equilibrium

Kinetics

The Main-Group Elements

The D-Block Elements

Nuclear Chemistry

Organic Chemistry

Filters

For NH₃, pK_b = 4.74.What is the pH of an aqueous buffer solution that is 0.050 M NH₃(aq)And 0.20 M NH₄Cl(aq)?

For a 0.10 M solution of a weak acid, HA,With pK_a = 10,Which of the following is true?

For the titration of 50.0 mL of 0.020 M aqueous salicylic acid with 0.020 M KOH(aq), calculate the pH after the addition of 55.0 mL of KOH(aq).For salycylic acid,PK_a = 2.97.

Given: N₂H₅⁺(aq) $\rarr$ N₂(g). How many electrons appear in the balanced half-reaction?

What is the proper cell diagram for the reaction 2AgCl(s)+ H₂(g) $\rightarrow$ 2Ag(s)+ 2H⁺(aq)+ 2Cl^-(aq)

Calculate the [H⁺] in an aqueous solution that is 0.0755 M HF and 0.100 M NaF .The value of K_a for HF is 3.5 * 10^-⁴.

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 electrode is negative?

What is the pH at the half-stoichiometric point for the titration of 0.88 M HNO₂(aq) with 0.10 M KOH(aq)? For HNO₂,K_a = 4.3 * 10^-⁴.

You have available the following reagents as 0.10 M aqueous solutions:NaOH,HCl,Phenol (pK_a = 9.89),Aniline (pK_b = 9.37),HNO₂ (pK_a = 3.37),CH₃NH₂ (pK_b = 3.44).Which two reagents would you use to make a buffer with a pH of 10.5?

A certain weak acid has a K_a of 2.0 *10^-⁵.What is the equilibrium constant for the reaction of this acid with a strong base?

A 0.0010 M solution of a weak acid, HA,With K_a = 2 * 10^-¹⁰ produces [H₃O⁺] < 10^-⁶ M.Which of the following equations can be used to determine [H₃O⁺]?

Calculate the equilibrium constant for the reaction that occurs when perchloric acid is added to the buffer B(aq)/BHCl(aq).The K_b of B is 3.4 * 10^-⁵.

In order to convert hydrazine, N₂H₄,To nitric acid,

For a solution labeled "0.10 M H₃PO₄(aq),"

Consider the titration of 10.0 mL of 0.100 M (CH₃)₃N(aq) with 0.100 M HClO₄(aq).What is the formula of the main species in the solution after the addition of 10.0 mL of acid?