Question 1

Calculate the equilibrium constant for the reaction
S2-(aq)+ H2O(l)$\Leftrightarrow$H-(aq)+ OH-(aq),
Given Ka1 = 1.3 * 10-7 and Ka2 = 7.1 * 10-15 for H2S.

Accepted Answer

A)  1.3 * 10-7  
B)  9.2 *10-22  
C)  7.7 * 10-8  
D)  7.1 * 10-15  
E)  1.4 
A)  1.3 * 10-7  
B)  9.2 *10-22  
C)  7.7 * 10-8  
D)  7.1 * 10-15  
E)  1.4

Question 2

In the titration of 0.300 M H3PO4(aq)with 0.300 M NaOH(aq),the first stoichiometric point occurs at pH  7.Explain.

Accepted Answer

H<sub>2</sub>PO<sub>4</sub><su

Question 3

In the following reaction
SO2(g)+ H2O(l)$\rightarrow$H2SO3(aq),
identify the Lewis acid and base.

Accepted Answer

Lewis acid

Question 4

HBrO(aq), in a 0.25 M solution,Has a pKa = 8.69.What is its pH?

Accepted Answer

A)  0.60 
B)  4.65 
C)  5.90 
D)  8.10 
E)  9.30 
A)  0.60 
B)  4.65 
C)  5.90 
D)  8.10 
E)  9.30

Question 5

A buffer solution contains 0.25 M NaNO2(aq) and 0.80 M HNO2(aq)
(pKa = 3.37).What is the pH after 0.10 mol HBr are added to 1.00 L of this buffer?

Accepted Answer

A)  11.41 
B)  4.15 
C)  2.59 
D)  9.85 
E)  3.37 
A)  11.41 
B)  4.15 
C)  2.59 
D)  9.85 
E)  3.37

Question 6

What is the concentration of acetate ion at the stoichiometric point in the titration of 0.018 M CH3COOH(aq) with 0.072 M NaOH(aq)? For acetic acid,
Ka = 1.8 * 10-5.

Accepted Answer

A)  0.054 M 
B)  0.036 M 
C)  0.018 M 
D)  0.072 M 
E)  0.014 M 
A)  0.054 M 
B)  0.036 M 
C)  0.018 M 
D)  0.072 M 
E)  0.014 M

Question 7

Calculate the equilibrium constant for the reaction
HS-(aq)+ H2O(l)$\Leftrightarrow$ H2S(aq)+ OH-(aq), Given Ka1 = 1.3 * 10-7 and Ka2 = 7.1 * 10-15 for H2S.

Accepted Answer

A)  1.3 * 10-7  
B)  7.7 * 10-8  
C)  9.2 * 10-22  
D)  7.1 * 10-15  
E)  1.4 
A)  1.3 * 10-7  
B)  7.7 * 10-8  
C)  9.2 * 10-22  
D)  7.1 * 10-15  
E)  1.4

Question 8

Consider the following cell:
Zn(s)|Zn2+(aq,0.100 M)M Cl-(aq,? M)|Cl2(g,0.500 atm)|Pt
For this cell,
E$\omicron$ = 2.12 V and E = 2.27 V at 25$\omicron$C.Calculate the Cl-(aq)
Concentration in the cathode compartment.

Accepted Answer

A)  1.2 * 10-1 M 
B)  4.3 * 10-5 M 
C)  2.9 * 10-3 M 
D)  1.5 * 10-3 M 
E)  6.5 * 10-3 M 
A)  1.2 * 10-1 M 
B)  4.3 * 10-5 M 
C)  2.9 * 10-3 M 
D)  1.5 * 10-3 M 
E)  6.5 * 10-3 M

Question 9

Which of the following is not a Lewis acid?

Accepted Answer

A)  H3O+ 
B)  SO3 
C)  NO2- 
D)  BF3  
E)  BCl3 
A)  H3O+ 
B)  SO3 
C)  NO2- 
D)  BF3  
E)  BCl3

Question 10

If the standard potentials for the couples Cu2+/Cu, Ag+/Ag,And Fe2+/Fe are+0.34,+0.80,And -0.44 V,Respectively,Which is the strongest reducing agent?

Accepted Answer

A)  Fe 
B)  Ag 
C)  Ag+  
D)  Cu 
E)  Fe2+  
A)  Fe 
B)  Ag 
C)  Ag+  
D)  Cu 
E)  Fe2+

Question 11

If the standard potentials for the couples Fe3+/Fe2+, MnO42-,H+/Mn2+,H2O,Zn2+/Zn,V3+/V2+,And Br2/Br- are +0.77,+1.51,-0.76,-0.26,And +1.09 V,Respectively,Which is the strongest oxidizing agent?

Accepted Answer

A)  Zn2+  
B)  Fe3+  
C)  Mn2+  
D)  Br2  
E)  MnO4-  
A)  Zn2+  
B)  Fe3+  
C)  Mn2+  
D)  Br2  
E)  MnO4-

Question 12

Strong acids are leveled in water to the strength of the acid H3O+.

Accepted Answer

A) True 
 B)False

Question 13

If the standard free energy change for combustion of 1 mole of CH4(g) is -818 kJ.mol-1,Calculate the standard voltage that could be obtained from a fuel cell using this reaction.

Accepted Answer

A)  -1.06 V 
B)  +0.53 V 
C)  +4.24 V 
D)  +8.48 V 
E)  +1.06 V 
A)  -1.06 V 
B)  +0.53 V 
C)  +4.24 V 
D)  +8.48 V 
E)  +1.06 V

Question 14

The amino acid alanine, HOOC-CH(CH3)NH3+,Has Ka1 = 4.5 * 10-3 and Ka2 = 1.4 * 10-10.Calculate $\alpha$(-OOC-CH(CH3)NH3+)At pH 3.

Accepted Answer

A)  0 
B)  0.82 
C)  0.18 
D)  0.29 
E)  0.58 
A)  0 
B)  0.82 
C)  0.18 
D)  0.29 
E)  0.58

Question 15

In liquid ammonia,the base B is a strong base if it is a stronger proton acceptor than NH2-.

Accepted Answer

A) True 
 B)False

Question 16

How long will it take to deposit 0.00235 moles of gold by electrolysis of KAuCl4(aq) using a current of 0.214 amperes?

Accepted Answer

A)  17.7 min 
B)  26.5 min 
C)  70.7 min 
D)  106 min 
E)  53.0 min 
A)  17.7 min 
B)  26.5 min 
C)  70.7 min 
D)  106 min 
E)  53.0 min

Question 17

For a solution of phosphoric acid, write the equation for (HPO42-).

Accepted Answer

A)  Ka3/([H3O+]3 + Ka1[H3O+]2 + Ka1Ka2[H3O+] + Ka1Ka2Ka3) 
B)  [H3O+]/([H3O+]3 + Ka1[H3O+]2 + Ka1Ka2[H3O+] + Ka1Ka2Ka3) 
C)  Ka1Ka2[H3O+]/([H3O+]3 + Ka1[H3O+]2 + Ka1Ka2[H3O+] + Ka1Ka2Ka3) 
D)  Ka1Ka2Ka3/([H3O+]3 + Ka1[H3O+]2 + Ka1Ka2[H3O+] + Ka1Ka2Ka3) 
E)  Ka1[H3O+]2/([H3O+]3 + Ka1[H3O+]2 + Ka1Ka2[H3O+] + Ka1Ka2Ka3) 
A)  Ka3/([H3O+]3 + Ka1[H3O+]2 + Ka1Ka2[H3O+] + Ka1Ka2Ka3) 
B)  [H3O+]/([H3O+]3 + Ka1[H3O+]2 + Ka1Ka2[H3O+] + Ka1Ka2Ka3) 
C)  Ka1Ka2[H3O+]/([H3O+]3 + Ka1[H3O+]2 + Ka1Ka2[H3O+] + Ka1Ka2Ka3) 
D)  Ka1Ka2Ka3/([H3O+]3 + Ka1[H3O+]2 + Ka1Ka2[H3O+] + Ka1Ka2Ka3) 
E)  Ka1[H3O+]2/([H3O+]3 + Ka1[H3O+]2 + Ka1Ka2[H3O+] + Ka1Ka2Ka3)

Question 18

What is the pH of an aqueous solution that is 0.12 M C6H5NH2 (Kb = 4.3 * 10-10) and 0.018 M C6H5NH3Cl?

Accepted Answer

A)  5.46 
B)  10.19 
C)  4.63 
D)  3.81 
E)  8.54 
A)  5.46 
B)  10.19 
C)  4.63 
D)  3.81 
E)  8.54

Question 19

When pyridinium chloride is added to C5H5N(aq),

Accepted Answer

A)  the pH of the solution does not change. 
B)  the pH of the solution increases. 
C)  the pH of the solution decreases. 
D)  the Kb increases. 
E)  the equilibrium concentration of NH3(aq) decreases. 
A)  the pH of the solution does not change. 
B)  the pH of the solution increases. 
C)  the pH of the solution decreases. 
D)  the Kb increases. 
E)  the equilibrium concentration of NH3(aq) decreases.

Question 20

Which of the following indicators would be most suitable for the titration of 0.10 M (CH3)3N(aq) with 0.10 M HClO4(aq)? For trimethyamine,PKb = 4.19.

Accepted Answer

A)  Bromothymol blue (pKIn = 7.1) 
B)  Alizarin yellow (pKIn = 11.2) 
C)  Bromocresol green (pKIn = 4.7) 
D)  Tthymol blue (pKIn = 1.7) 
E)  Phenolphthalein (pKIn = 9.4) 
A)  Bromothymol blue (pKIn = 7.1) 
B)  Alizarin yellow (pKIn = 11.2) 
C)  Bromocresol green (pKIn = 4.7) 
D)  Tthymol blue (pKIn = 1.7) 
E)  Phenolphthalein (pKIn = 9.4)

Calculate the equilibrium constant for the reaction S²^-(aq)+ H₂O(l) $\Leftrightarrow$ H^-(aq)+ OH^-(aq), Given K_a1 = 1.3 * 10^-⁷ and K_a2 = 7.1 * 10^-¹⁵ for H₂S.

In the titration of 0.300 M H₃PO₄(aq)with 0.300 M NaOH(aq),the first stoichiometric point occurs at pH < 7 whereas in the titration of 0.300 M HCOOH(aq)with 0.300 M NaOH(aq)the stoichiometric point occurs at pH > 7.Explain.

In the following reaction SO₂(g)+ H₂O(l) $\rightarrow$ H₂SO₃(aq), identify the Lewis acid and base.

HBrO(aq), in a 0.25 M solution,Has a pK_a = 8.69.What is its pH?

A buffer solution contains 0.25 M NaNO₂(aq) and 0.80 M HNO₂(aq) (pK_a = 3.37).What is the pH after 0.10 mol HBr are added to 1.00 L of this buffer?

What is the concentration of acetate ion at the stoichiometric point in the titration of 0.018 M CH₃COOH(aq) with 0.072 M NaOH(aq)? For acetic acid, K_a = 1.8 * 10^-⁵.

Calculate the equilibrium constant for the reaction HS^-(aq)+ H₂O(l) $\Leftrightarrow$ H₂S(aq)+ OH^-(aq), Given K_a1 = 1.3 * 10^-⁷ and K_a2 = 7.1 * 10^-¹⁵ for H₂S.

Consider the following cell: Zn(s)|Zn²⁺(aq,0.100 M)M Cl^-(aq,? M)|Cl₂(g,0.500 atm)|Pt For this cell, E^$\omicron$ = 2.12 V and E = 2.27 V at 25^$\omicron$C.Calculate the Cl^-(aq) Concentration in the cathode compartment.

Which of the following is not a Lewis acid?

If the standard potentials for the couples Cu²⁺/Cu, Ag⁺/Ag,And Fe²⁺/Fe are+0.34,+0.80,And -0.44 V,Respectively,Which is the strongest reducing agent?

If the standard potentials for the couples Fe³⁺/Fe²⁺, MnO₄2^-,H⁺/Mn²⁺,H₂O,Zn²⁺/Zn,V³⁺/V²⁺,And Br₂/Br^- are +0.77,+1.51,-0.76,-0.26,And +1.09 V,Respectively,Which is the strongest oxidizing agent?

Strong acids are leveled in water to the strength of the acid H₃O⁺.

If the standard free energy change for combustion of 1 mole of CH₄(g) is -818 kJ.mol^{-¹,Calculate the standard voltage that could be obtained from a fuel cell using this reaction.}

The amino acid alanine, HOOC-CH(CH₃)NH₃⁺,Has K_a1 = 4.5 * 10^-³ and K_a2 = 1.4 * 10^-¹⁰.Calculate $\alpha$ (^-OOC-CH(CH₃)NH₃⁺)At pH 3.

In liquid ammonia,the base B is a strong base if it is a stronger proton acceptor than NH₂^-.

How long will it take to deposit 0.00235 moles of gold by electrolysis of KAuCl₄(aq) using a current of 0.214 amperes?

For a solution of phosphoric acid, write the equation for (HPO₄²^-).

What is the pH of an aqueous solution that is 0.12 M C₆H₅NH₂ (K_b = 4.3 * 10^-¹⁰) and 0.018 M C₆H₅NH₃Cl?

When pyridinium chloride is added to C₅H₅N(aq),

Which of the following indicators would be most suitable for the titration of 0.10 M (CH₃)₃N(aq) with 0.10 M HClO₄(aq)? For trimethyamine,PK_b = 4.19.

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Exam 6: Reactions

Calculate the equilibrium constant for the reaction S2-(aq)+ H2O(l) ⇔\Leftrightarrow⇔ H-(aq)+ OH-(aq), Given Ka1 = 1.3 * 10-7 and Ka2 = 7.1 * 10-15 for H2S.

In the titration of 0.300 M H3PO4(aq)with 0.300 M NaOH(aq),the first stoichiometric point occurs at pH < 7 whereas in the titration of 0.300 M HCOOH(aq)with 0.300 M NaOH(aq)the stoichiometric point occurs at pH > 7.Explain.

In the following reaction SO2(g)+ H2O(l) →\rightarrow→ H2SO3(aq), identify the Lewis acid and base.

HBrO(aq), in a 0.25 M solution,Has a pKa = 8.69.What is its pH?

A buffer solution contains 0.25 M NaNO2(aq) and 0.80 M HNO2(aq) (pKa = 3.37).What is the pH after 0.10 mol HBr are added to 1.00 L of this buffer?

What is the concentration of acetate ion at the stoichiometric point in the titration of 0.018 M CH3COOH(aq) with 0.072 M NaOH(aq)? For acetic acid, Ka = 1.8 * 10-5.

Calculate the equilibrium constant for the reaction HS-(aq)+ H2O(l) ⇔\Leftrightarrow⇔ H2S(aq)+ OH-(aq), Given Ka1 = 1.3 * 10-7 and Ka2 = 7.1 * 10-15 for H2S.

Consider the following cell: Zn(s)|Zn2+(aq,0.100 M)M Cl-(aq,? M)|Cl2(g,0.500 atm)|Pt For this cell, E ο\omicronο = 2.12 V and E = 2.27 V at 25 ο\omicronο C.Calculate the Cl-(aq) Concentration in the cathode compartment.

Which of the following is not a Lewis acid?

If the standard potentials for the couples Cu2+/Cu, Ag+/Ag,And Fe2+/Fe are+0.34,+0.80,And -0.44 V,Respectively,Which is the strongest reducing agent?

If the standard potentials for the couples Fe3+/Fe2+, MnO42-,H+/Mn2+,H2O,Zn2+/Zn,V3+/V2+,And Br2/Br- are +0.77,+1.51,-0.76,-0.26,And +1.09 V,Respectively,Which is the strongest oxidizing agent?

Strong acids are leveled in water to the strength of the acid H3O+.

If the standard free energy change for combustion of 1 mole of CH4(g) is -818 kJ.mol-1,Calculate the standard voltage that could be obtained from a fuel cell using this reaction.

The amino acid alanine, HOOC-CH(CH3)NH3+,Has Ka1 = 4.5 * 10-3 and Ka2 = 1.4 * 10-10.Calculate α\alphaα (-OOC-CH(CH3)NH3+)At pH 3.

In liquid ammonia,the base B is a strong base if it is a stronger proton acceptor than NH2-.

How long will it take to deposit 0.00235 moles of gold by electrolysis of KAuCl4(aq) using a current of 0.214 amperes?

For a solution of phosphoric acid, write the equation for (HPO42-).

What is the pH of an aqueous solution that is 0.12 M C6H5NH2 (Kb = 4.3 * 10-10) and 0.018 M C6H5NH3Cl?

When pyridinium chloride is added to C5H5N(aq),

Which of the following indicators would be most suitable for the titration of 0.10 M (CH3)3N(aq) with 0.10 M HClO4(aq)? For trimethyamine,PKb = 4.19.

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Calculate the equilibrium constant for the reaction S²^-(aq)+ H₂O(l) $\Leftrightarrow$ H^-(aq)+ OH^-(aq), Given K_a1 = 1.3 * 10^-⁷ and K_a2 = 7.1 * 10^-¹⁵ for H₂S.

In the titration of 0.300 M H₃PO₄(aq)with 0.300 M NaOH(aq),the first stoichiometric point occurs at pH < 7 whereas in the titration of 0.300 M HCOOH(aq)with 0.300 M NaOH(aq)the stoichiometric point occurs at pH > 7.Explain.

In the following reaction SO₂(g)+ H₂O(l) $\rightarrow$ H₂SO₃(aq), identify the Lewis acid and base.

HBrO(aq), in a 0.25 M solution,Has a pK_a = 8.69.What is its pH?

A buffer solution contains 0.25 M NaNO₂(aq) and 0.80 M HNO₂(aq) (pK_a = 3.37).What is the pH after 0.10 mol HBr are added to 1.00 L of this buffer?

What is the concentration of acetate ion at the stoichiometric point in the titration of 0.018 M CH₃COOH(aq) with 0.072 M NaOH(aq)? For acetic acid, K_a = 1.8 * 10^-⁵.

Calculate the equilibrium constant for the reaction HS^-(aq)+ H₂O(l) $\Leftrightarrow$ H₂S(aq)+ OH^-(aq), Given K_a1 = 1.3 * 10^-⁷ and K_a2 = 7.1 * 10^-¹⁵ for H₂S.

Consider the following cell: Zn(s)|Zn²⁺(aq,0.100 M)M Cl^-(aq,? M)|Cl₂(g,0.500 atm)|Pt For this cell, E^$\omicron$ = 2.12 V and E = 2.27 V at 25^$\omicron$C.Calculate the Cl^-(aq) Concentration in the cathode compartment.

If the standard potentials for the couples Cu²⁺/Cu, Ag⁺/Ag,And Fe²⁺/Fe are+0.34,+0.80,And -0.44 V,Respectively,Which is the strongest reducing agent?

If the standard potentials for the couples Fe³⁺/Fe²⁺, MnO₄2^-,H⁺/Mn²⁺,H₂O,Zn²⁺/Zn,V³⁺/V²⁺,And Br₂/Br^- are +0.77,+1.51,-0.76,-0.26,And +1.09 V,Respectively,Which is the strongest oxidizing agent?

Strong acids are leveled in water to the strength of the acid H₃O⁺.

If the standard free energy change for combustion of 1 mole of CH₄(g) is -818 kJ.mol^{-¹,Calculate the standard voltage that could be obtained from a fuel cell using this reaction.}

The amino acid alanine, HOOC-CH(CH₃)NH₃⁺,Has K_a1 = 4.5 * 10^-³ and K_a2 = 1.4 * 10^-¹⁰.Calculate $\alpha$ (^-OOC-CH(CH₃)NH₃⁺)At pH 3.

In liquid ammonia,the base B is a strong base if it is a stronger proton acceptor than NH₂^-.

How long will it take to deposit 0.00235 moles of gold by electrolysis of KAuCl₄(aq) using a current of 0.214 amperes?

For a solution of phosphoric acid, write the equation for (HPO₄²^-).

What is the pH of an aqueous solution that is 0.12 M C₆H₅NH₂ (K_b = 4.3 * 10^-¹⁰) and 0.018 M C₆H₅NH₃Cl?

When pyridinium chloride is added to C₅H₅N(aq),

Which of the following indicators would be most suitable for the titration of 0.10 M (CH₃)₃N(aq) with 0.10 M HClO₄(aq)? For trimethyamine,PK_b = 4.19.