Question 1

What is the equilibrium pH of a 0.835 M solution of H3PO4(aq)? (Ka1 = 7.5 $\times$10-3,Ka2 = 6.2 $\times$10-8,Ka3 = 4.8 $\times$10-13)

Accepted Answer

A) 1.12 
B) 3.64 
C) 12.32 
D) 6.20 
E) 7.21 
A) 1.12 
B) 3.64 
C) 12.32 
D) 6.20 
E) 7.21

Question 2

The equilibrium constants (Ka)for HCN and HF in H2O at 25°C are 6.2 $\times$ 10-10 and 7.2 $\times$ 10-4,respectively.The relative order of base strengths is:

Accepted Answer

A) F- > H2O > CN- 
B) H2O > F- > CN- 
C) CN- > F- > H2O 
D) F- > CN- > H2O 
E) none of these 
A) F- > H2O > CN- 
B) H2O > F- > CN- 
C) CN- > F- > H2O 
D) F- > CN- > H2O 
E) none of these

Question 3

At 65°C,the ion-product constant of water,Kw,is 1.20 $\times$ 10-13.The pH of pure water at 65°C is:

Accepted Answer

A) 7.000 
B) 6.560 
C) 5.880 
D) 6.460 
E) none of these 
A) 7.000 
B) 6.560 
C) 5.880 
D) 6.460 
E) none of these

Question 4

Determine whether the following oxides produce an acidic,basic,or neutral solution when dissolved in water:
-Cl2O

Accepted Answer

acidic Cl₂

Question 5

A solution of 8.01 M formic acid (HCOOH)is 0.47% ionized.What is the Ka value of formic acid?

Accepted Answer

A) 3.8 $\times$ 10-2 
B) 1.8 $\times$ 10-4 
C) 4.7 $\times$ 10-3 
D) 3.8 
E) more data is needed 
A) 3.8 $\times$ 10-2 
B) 1.8 $\times$ 10-4 
C) 4.7 $\times$ 10-3 
D) 3.8 
E) more data is needed

Question 6

Select the answer that best describes an aqueous solution made from each of the following substances:
-solid aluminum chloride (AlCl3)

Accepted Answer

A) acidic 
B) basic 
C) neutral 
D) cannot tell 
E) none of these (A-
D)  
A) acidic 
B) basic 
C) neutral 
D) cannot tell 
E) none of these (A-
D)

Question 7

The [H3O+] of a 0.49 M solution of NH4Cl in H2O at 25°C is (Kb for NH3 = 1.8 $\times$ 10-5):

Accepted Answer

A) 2.7 $\times$ 10-10 M 
B) 3.0 $\times$ 10-3 M 
C) 1.6 $\times$10-5 M 
D) 0.49 M 
E) none of these 
A) 2.7 $\times$ 10-10 M 
B) 3.0 $\times$ 10-3 M 
C) 1.6 $\times$10-5 M 
D) 0.49 M 
E) none of these

Question 8

Given the following acids and Ka values: 
 
What is the order of increasing base strength?

Accepted Answer

A) CN-,F-,OAc-,ClO4- 
B) CN-,OAc-,F-,ClO4- 
C) CN-,ClO4-,F-,OAc- 
D) ClO4-,OAc-,CN-,F- 
E) ClO4-,F-,OAc-,CN- 
A) CN-,F-,OAc-,ClO4- 
B) CN-,OAc-,F-,ClO4- 
C) CN-,ClO4-,F-,OAc- 
D) ClO4-,OAc-,CN-,F- 
E) ClO4-,F-,OAc-,CN-

Question 9

Calculate the pH of the following aqueous solution: 0.39 M NH4Cl (pKb for NH3 = 4.74)

Accepted Answer

A) 9.17 
B) 4.83 
C) 9.67 
D) 4.33 
E) none of these 
A) 9.17 
B) 4.83 
C) 9.67 
D) 4.33 
E) none of these

Question 10

Carbonic acid is a diprotic acid,H2CO3,with Ka1 = 4.2 $\times$ 10-7 and Ka2 = 4.8 $\times$ 10-11 at 25°C.The ion product for water is Kw = 1.0 $\times$ 10-14 at 25°C.What is the OH- concentration of a solution that is 0.18 M in Na2CO3?

Accepted Answer

A) 6.1 $\times$10-3 M 
B) 2.1 $\times$ 10-4 M 
C) 6.5 $\times$ 10-5 M 
D) 2.9 $\times$ 10-6 M 
E) 2.7 $\times$10-4 M 
A) 6.1 $\times$10-3 M 
B) 2.1 $\times$ 10-4 M 
C) 6.5 $\times$ 10-5 M 
D) 2.9 $\times$ 10-6 M 
E) 2.7 $\times$10-4 M

Question 11

Explain why Al2(SO4)3 produces an acidic solution when it is dissolved in water.

Accepted Answer

The ions from this salt are: Al^3+</

Question 12

Calculate the pH of the following aqueous solution: 0.66 M HOCl (pKa = 7.46)

Accepted Answer

A) 10.18 
B) 3.82 
C) 7.64 
D) 6.36 
E) none of these 
A) 10.18 
B) 3.82 
C) 7.64 
D) 6.36 
E) none of these

Question 13

Calculate the [H+] in a 0.068 M solution of HCN,Ka = 6.2 $\times$10-10.

Accepted Answer

A) 1.0 $\times$10-7 M 
B) 6.5 $\times$ 10-6 M 
C) 4.2 $\times$10-11 M 
D) 1.3 $\times$ 10-5 M 
E) none of these 
A) 1.0 $\times$10-7 M 
B) 6.5 $\times$ 10-6 M 
C) 4.2 $\times$10-11 M 
D) 1.3 $\times$ 10-5 M 
E) none of these

Question 14

Calculate the pH of a 0.005 M solution of potassium oxide,K2O.

Accepted Answer

A) 12.0 
B) 11.7 
C) 7.0 
D) 2.3 
E) 2.0 
A) 12.0 
B) 11.7 
C) 7.0 
D) 2.3 
E) 2.0

Question 15

Calculate the pH of a 0.59 M solution of NH4Cl.(Kb for NH3 = 1.8 $\times$ 10-5)

Accepted Answer

A) 9.26 
B) 4.74 
C) 9.48 
D) 4.52 
E) 0.23 
A) 9.26 
B) 4.74 
C) 9.48 
D) 4.52 
E) 0.23

Question 16

Consider the following reactions:
a)AlS1U1P13+S1S1P0 + 6HS1U1B12S1U1B0O   Al(OHS1U1B12S1U1B0)S1U1B16S1U1B0S1U1P13+S1S1P0
b)Al(OHS1U1B12S1U1B0)S1U1B16S1U1B0S1U1P13+S1S1P0   Al(OH)(OHS1U1B12S1U1B0)S1U1B15S1U1B0S1U1P12+S1S1P0 + HS1U1P1+S1S1P0
c)OClS1U1P1-S1S1P0 + HS1U1B12S1U1B0O   HOCl + OHS1U1P1-S1S1P0
d)CNS1U1P1-S1S1P0 + HS1U1P1+S1S1P0   HCN
e)none of these
-Which is associated with the definition of Ka?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 17

Which of the following species cannot act as a Lewis base?

Accepted Answer

A) N3- 
B) NH2- 
C) NH2- 
D) NH3 
E) NH4+ 
A) N3- 
B) NH2- 
C) NH2- 
D) NH3 
E) NH4+

Question 18

What concentration of acetic acid (Ka = 1.80 $\times$10-5)has the same pH as that of 5.33 $\times$ 10-3 M HCl?

Accepted Answer

A) 17.2 M 
B) 12.4 M 
C) 1.58 M 
D) 5.33 $\times$10-3 M 
E) none of these 
A) 17.2 M 
B) 12.4 M 
C) 1.58 M 
D) 5.33 $\times$10-3 M 
E) none of these

Question 19

Define amphoteric substance.

Accepted Answer

A substance that can behave ei

Question 20

For the stepwise dissociation of aqueous H3PO4,which of the following is not a conjugate acid-base pair?

Accepted Answer

A) HPO42- and PO43- 
B) H3PO4 and H2PO4- 
C) H2PO4- and HPO42- 
D) H2PO4- and PO43- 
E) H3O+ and H2O 
A) HPO42- and PO43- 
B) H3PO4 and H2PO4- 
C) H2PO4- and HPO42- 
D) H2PO4- and PO43- 
E) H3O+ and H2O

Exam 14: Acids and Bases

What is the equilibrium pH of a 0.835 M solution of H3PO4(aq)? (Ka1 = 7.5 ×\times× 10-3,Ka2 = 6.2 ×\times× 10-8,Ka3 = 4.8 ×\times× 10-13)

The equilibrium constants (Ka)for HCN and HF in H2O at 25°C are 6.2 ×\times× 10-10 and 7.2 ×\times× 10-4,respectively.The relative order of base strengths is:

At 65°C,the ion-product constant of water,Kw,is 1.20 ×\times× 10-13.The pH of pure water at 65°C is:

Determine whether the following oxides produce an acidic,basic,or neutral solution when dissolved in water: -Cl2O

A solution of 8.01 M formic acid (HCOOH)is 0.47% ionized.What is the Ka value of formic acid?

Select the answer that best describes an aqueous solution made from each of the following substances: -solid aluminum chloride (AlCl3)

The [H3O+] of a 0.49 M solution of NH4Cl in H2O at 25°C is (Kb for NH3 = 1.8 ×\times× 10-5):

Given the following acids and Ka values: What is the order of increasing base strength?

Calculate the pH of the following aqueous solution: 0.39 M NH4Cl (pKb for NH3 = 4.74)

Carbonic acid is a diprotic acid,H2CO3,with Ka1 = 4.2 ×\times× 10-7 and Ka2 = 4.8 ×\times× 10-11 at 25°C.The ion product for water is Kw = 1.0 ×\times× 10-14 at 25°C.What is the OH- concentration of a solution that is 0.18 M in Na2CO3?

Explain why Al2(SO4)3 produces an acidic solution when it is dissolved in water.

Calculate the pH of the following aqueous solution: 0.66 M HOCl (pKa = 7.46)

Calculate the [H+] in a 0.068 M solution of HCN,Ka = 6.2 ×\times× 10-10.

Calculate the pH of a 0.005 M solution of potassium oxide,K2O.

Calculate the pH of a 0.59 M solution of NH4Cl.(Kb for NH3 = 1.8 ×\times× 10-5)

Consider the following reactions: a)Al3+ + 6H2O Al(OH2)63+ b)Al(OH2)63+ Al(OH)(OH2)52+ + H+ c)OCl- + H2O HOCl + OH- d)CN- + H+ HCN e)none of these -Which is associated with the definition of Ka?

Which of the following species cannot act as a Lewis base?

What concentration of acetic acid (Ka = 1.80 ×\times× 10-5)has the same pH as that of 5.33 ×\times× 10-3 M HCl?

Define amphoteric substance.

For the stepwise dissociation of aqueous H3PO4,which of the following is not a conjugate acid-base pair?

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What is the equilibrium pH of a 0.835 M solution of H₃PO₄(aq)? (K_a1 = 7.5 $\times$ 10^-³,K_a2 = 6.2 $\times$ 10^-⁸,K_a3 = 4.8 $\times$ 10^-¹³)

The equilibrium constants (K_a)for HCN and HF in H₂O at 25°C are 6.2 $\times$ 10^-¹⁰ and 7.2 $\times$ 10^-⁴,respectively.The relative order of base strengths is:

At 65°C,the ion-product constant of water,K_w,is 1.20 $\times$ 10^-¹³.The pH of pure water at 65°C is:

Determine whether the following oxides produce an acidic,basic,or neutral solution when dissolved in water: -Cl₂O

A solution of 8.01 M formic acid (HCOOH)is 0.47% ionized.What is the K_a value of formic acid?

Select the answer that best describes an aqueous solution made from each of the following substances: -solid aluminum chloride (AlCl₃)

The [H₃O⁺] of a 0.49 M solution of NH₄Cl in H₂O at 25°C is (K_b for NH₃ = 1.8 $\times$ 10^-⁵):

Given the following acids and K_a values: What is the order of increasing base strength?

Calculate the pH of the following aqueous solution: 0.39 M NH₄Cl (pK_b for NH₃ = 4.74)

Carbonic acid is a diprotic acid,H₂CO₃,with K_a1 = 4.2 $\times$ 10^-⁷ and K_a2 = 4.8 $\times$ 10^-¹¹ at 25°C.The ion product for water is K_w = 1.0 $\times$ 10^-¹⁴ at 25°C.What is the OH^- concentration of a solution that is 0.18 M in Na₂CO₃?

Explain why Al₂(SO₄)₃ produces an acidic solution when it is dissolved in water.

Calculate the pH of the following aqueous solution: 0.66 M HOCl (pK_a = 7.46)

Calculate the [H⁺] in a 0.068 M solution of HCN,K_a = 6.2 $\times$ 10^-¹⁰.

Calculate the pH of a 0.005 M solution of potassium oxide,K₂O.

Calculate the pH of a 0.59 M solution of NH₄Cl.(K_b for NH₃ = 1.8 $\times$ 10^-⁵)

Consider the following reactions: a)Al³⁺ + 6H₂O Al(OH₂)₆³⁺ b)Al(OH₂)₆³⁺ Al(OH)(OH₂)₅²⁺ + H⁺ c)OCl^- + H₂O HOCl + OH^- d)CN^- + H⁺ HCN e)none of these -Which is associated with the definition of K_a?

What concentration of acetic acid (K_a = 1.80 $\times$ 10^-⁵)has the same pH as that of 5.33 $\times$ 10^-³M HCl?

For the stepwise dissociation of aqueous H₃PO₄,which of the following is not a conjugate acid-base pair?