Question 1

Which of these species will act as a Lewis acid?

Accepted Answer

A)  NH3
B)  NH4+
C)  H2O
D)  BF3
E)  F-

Question 2

Which one of these net ionic equations represents the reaction of a strong acid with a weak base?

Accepted Answer

A)  H+(aq) + OH-(aq)  →\rarr→  H2O(aq) 
B)  H+(aq) + CH3NH2(aq)  →\rarr→ CH3NH3+(aq) 
C)  OH-(aq) + HCN(aq)  →\rarr→ H2O(aq) + CN-(aq) 
D)  HCN(aq) + CH3NH2(aq)  →\rarr→ CH3NH3+  (aq) + CN-(aq)

Question 3

Calculate the pH of a 0.021 M NaCN solution. [Ka(HCN) = 4.9 * 10-10]

Accepted Answer

A)  1.68
B)  3.18
C)  5.49
D)  7.00
E)  10.82

Question 4

Calculate the concentration of chromate ion (CrO42-) in a 0.450 M solution of chromic acid (H2CrO4) . [For chromic acid, Ka1 = 0.18, Ka2 = 3.2 * 10-7.]

Accepted Answer

A)  3.2 * 10-7 M
B)  1.5 * 10-6 M
C)  0.081 M
D)  1.1 * 10-6 M
E)  0.21 M

Question 5

Which solution will have the lowest pH?

Accepted Answer

A)  0.10 M HCN
B)  0.10 M HNO3
C)  0.10 M NaCl
D)  0.10 M H2CO3
E)  0.10 M NaOH

Question 6

Which one of these statements about strong acids is true?

Accepted Answer

A)  All strong acids have H atoms bonded to electronegative oxygen atoms.
B)  Strong acids are 100% ionized in water.
C)  The conjugate base of a strong acid is itself a strong base.
D)  Strong acids are very concentrated acids.
E)  Strong acids produce solutions with a higher pH than weak acids.

Question 7

What is the pH of a 0.001 M Ca(OH) 2 solution?

Accepted Answer

A)  3.0
B)  11.0
C)  2.7
D)  17.0
E)  11.3

Question 8

What mass of ammonium chloride must be added to 250. mL of water to give a solution with pH = 4.85? [Kb(NH3) = 1.8 * 10-5]

Accepted Answer

A)  4.7 g
B)  75 g
C)  2.3 * 10-3 g
D)  19 g
E)  10. g

Question 9

Will a 0.1 M solution of NH4CN(aq)be acidic, basic, or neutral?

Accepted Answer

Question 10

What is the pH of a 0.20 M solution of NH4Cl? [Kb(NH3) = 1.8 * 10-5]

Accepted Answer

A)  3.74
B)  4.98
C)  6.53
D)  9.02
E)  10.25

Question 11

Aspartic acid (C4H7NO4) , one of the 20 essential amino acids, has two ionizable hydrogens. At 25°C, Ka1 = 1.38 * 10-4 and Ka2 = 1.51 * 10-10. What is the concentration of doubly ionized aspartate ions in a 0.125 M aqueous solution of aspartic acid?

Accepted Answer

A)  3.33 * 10-2 M
B)  4.16 * 10-3 M
C)  4.15 * 10-3 M
D)  1.51 * 10-10 M
E)  2.08 * 10-14 M

Question 12

The pH of tomato juice is about 4.5. Calculate the concentration of hydrogen ions in this juice.

Accepted Answer

A)  3. * 10-10 M
B)  3. * 10-5 M
C)  5. * 10-4 M
D)  4. M
E)  3. * 1010 M

Question 13

HCN is classified as a weak acid in water. What does this classification mean?

Accepted Answer

A relatively small f...

Question 14

Due to a highway accident, 150 L of concentrated hydrochloric acid (12.0 M) is released into a lake containing 5.0 * 105 m3 of water. If the pH of this lake was 7.0 prior to the accident, what is the pH of the lake following the accident?

Accepted Answer

A)  5.44
B)  8.56
C)  8.44
D)  5.56
E)  2.44

Question 15

Which one of these salts will form an acidic solution upon dissolving in water?

Accepted Answer

A)  LiBr
B)  NaF
C)  NH4Br
D)  KOH
E)  NaCN

Question 16

What mass of sodium nitrite must be added to 350. mL of water to give a solution with pH = 8.40? [Ka(HNO2) = 5.6 * 10-4]

Accepted Answer

A)  68 g
B)  1.7 * 10-4 g
C)  0.039 g
D)  8.3 g
E)  24 g

Question 17

For H3PO4, Ka1 = 7.3 * 10-3, Ka2 = 6.2 * 10-6, and Ka3 = 4.8 * 10-13. An aqueous solution of NaH2PO4 therefore would be

Accepted Answer

A)  neutral.
B)  basic.
C)  acidic.

Question 18

Calculate the pH of a 0.10 M HCN solution that is 0.0070% ionized.

Accepted Answer

A)  1.00
B)  0.00070
C)  3.15
D)  5.15
E)  7.00

Question 19

Calculate the pH of a carbonated beverage in which the hydrogen ion concentration is 3.4 * 10-4 M.

Accepted Answer

A)  2.34
B)  3.47
C)  6.01
D)  7.99
E)  10.53

Question 20

The equilibrium constant for the reaction C6H5COOH(aq) + CH3COO-(aq)  →\rarr→ 0 C6H5COO-(aq) + CH3COOH(aq) 
Is 3.6 at 25°C. If Ka for CH3COOH is 1.8 * 10-5, what is the acid dissociation constant for C6H5COOH?

Accepted Answer

A)  5.0 * 10-6
B)  6.5 * 10-5
C)  2.3 * 10-4
D)  8.3 * 10-5
E)  5.6 * 10-6

Exam 16: Acids and Bases

Which one of these statements about strong acids is true?

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Which of these species will act as a Lewis acid?

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The pH of tomato juice is about 4.5. Calculate the concentration of hydrogen ions in this juice.

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HCN is classified as a weak acid in water. What does this classification mean?

Correct AnswerverifiedA relatively small f...View AnswerShow Answer

Which one of these salts will form an acidic solution upon dissolving in water?

Correct AnswerverifiedShow Answer

The equilibrium constant for the reaction C6H5COOH(aq) + CH3COO-(aq) →\rarr→ 0 C6H5COO-(aq) + CH3COOH(aq) Is 3.6 at 25°C. If Ka for CH3COOH is 1.8 * 10-5, what is the acid dissociation constant for C6H5COOH?

Correct AnswerverifiedShow Answer

What is the pH of a 0.001 M Ca(OH) 2 solution?

Correct AnswerverifiedShow Answer

For H3PO4, Ka1 = 7.3 * 10-3, Ka2 = 6.2 * 10-6, and Ka3 = 4.8 * 10-13. An aqueous solution of NaH2PO4 therefore would be

Correct AnswerverifiedShow Answer

Which solution will have the lowest pH?

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What is the pH of a 0.20 M solution of NH4Cl? [Kb(NH3) = 1.8 * 10-5]

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Calculate the concentration of chromate ion (CrO42-) in a 0.450 M solution of chromic acid (H2CrO4) . [For chromic acid, Ka1 = 0.18, Ka2 = 3.2 * 10-7.]

Correct AnswerverifiedShow Answer

Aspartic acid (C4H7NO4) , one of the 20 essential amino acids, has two ionizable hydrogens. At 25°C, Ka1 = 1.38 * 10-4 and Ka2 = 1.51 * 10-10. What is the concentration of doubly ionized aspartate ions in a 0.125 M aqueous solution of aspartic acid?

Correct AnswerverifiedShow Answer

Calculate the pH of a carbonated beverage in which the hydrogen ion concentration is 3.4 * 10-4 M.

Correct AnswerverifiedShow Answer

Will a 0.1 M solution of NH4CN(aq)be acidic, basic, or neutral?

Correct AnswerverifiedShow Answer

Calculate the pH of a 0.10 M HCN solution that is 0.0070% ionized.

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Which one of these net ionic equations represents the reaction of a strong acid with a weak base?

Correct AnswerverifiedShow Answer

Due to a highway accident, 150 L of concentrated hydrochloric acid (12.0 M) is released into a lake containing 5.0 * 105 m3 of water. If the pH of this lake was 7.0 prior to the accident, what is the pH of the lake following the accident?

Correct AnswerverifiedShow Answer

What mass of sodium nitrite must be added to 350. mL of water to give a solution with pH = 8.40? [Ka(HNO2) = 5.6 * 10-4]

Correct AnswerverifiedShow Answer

Calculate the pH of a 0.021 M NaCN solution. [Ka(HCN) = 4.9 * 10-10]

Correct AnswerverifiedShow Answer

What mass of ammonium chloride must be added to 250. mL of water to give a solution with pH = 4.85? [Kb(NH3) = 1.8 * 10-5]

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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A relatively small f...
View Answer

Correct Answer
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The equilibrium constant for the reaction C₆H₅COOH(aq) + CH₃COO^-(aq) $\rarr$ 0 C₆H₅COO^-(aq) + CH₃COOH(aq) Is 3.6 at 25°C. If K_a for CH₃COOH is 1.8 * 10^-5, what is the acid dissociation constant for C₆H₅COOH?

Correct Answer
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What is the pH of a 0.001 M Ca(OH) ₂ solution?

Correct Answer
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For H₃PO₄, K_a1 = 7.3 * 10^-3, K_a2 = 6.2 * 10^-6, and K_a3 = 4.8 * 10^-13. An aqueous solution of NaH₂PO₄ therefore would be

Correct Answer
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Correct Answer
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What is the pH of a 0.20 M solution of NH₄Cl? [K_b(NH₃) = 1.8 * 10^-5]

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Calculate the concentration of chromate ion (CrO₄^2-) in a 0.450 M solution of chromic acid (H₂CrO₄) . [For chromic acid, K_a1 = 0.18, K_a2 = 3.2 * 10^-7.]

Correct Answer
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Aspartic acid (C₄H₇NO₄) , one of the 20 essential amino acids, has two ionizable hydrogens. At 25°C, K_a1 = 1.38 * 10^-4 and K_a2 = 1.51 * 10^-10. What is the concentration of doubly ionized aspartate ions in a 0.125 M aqueous solution of aspartic acid?

Correct Answer
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Calculate the pH of a carbonated beverage in which the hydrogen ion concentration is 3.4 * 10^-4 M.

Correct Answer
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Will a 0.1 M solution of NH₄CN(aq)be acidic, basic, or neutral?

Correct Answer
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Correct Answer
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Correct Answer
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Due to a highway accident, 150 L of concentrated hydrochloric acid (12.0 M) is released into a lake containing 5.0 * 10⁵ m³ of water. If the pH of this lake was 7.0 prior to the accident, what is the pH of the lake following the accident?

Correct Answer
verified

What mass of sodium nitrite must be added to 350. mL of water to give a solution with pH = 8.40? [K_a(HNO₂) = 5.6 * 10^-4]

Correct Answer
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Calculate the pH of a 0.021 M NaCN solution. [K_a(HCN) = 4.9 * 10^-10]

Correct Answer
verified

What mass of ammonium chloride must be added to 250. mL of water to give a solution with pH = 4.85? [K_b(NH₃) = 1.8 * 10^-5]

Correct Answer
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