Question 1

A sodium hydroxide solution has a pH of 11.40. What is its [H3O+]?

Accepted Answer

A)  4.0 × 10−26 M 
B)  4.0 × 10−12 M 
C)  2.5 × 10−3 M 
D)  2.5 × 1011 M 
A)  4.0 × 10−26 M 
B)  4.0 × 10−12 M 
C)  2.5 × 10−3 M 
D)  2.5 × 1011 M

Question 2

Which of the following acids is found in gastric fluid?

Accepted Answer

A)  acetic 
B)  hydrochloric 
C)  nitric 
D)  sulfuric 
A)  acetic 
B)  hydrochloric 
C)  nitric 
D)  sulfuric

Question 3

A solution has a pOH of 7.4. What is its pH?

Accepted Answer

A)  -6.6 
B)  -7.4 
C)  7.4 
D)  6.6 
A)  -6.6 
B)  -7.4 
C)  7.4 
D)  6.6

Question 4

Which of the following must be increased in order to decrease the buffer capacity of a buffer made using acetic acid and sodium acetate?

Accepted Answer

A)  the amount of water present 
B)  [C2H3O2−] 
C)  [HC2H3O2] 
D)  the ratio of [C2H3O2−]/[HC2H3O2] 
A)  the amount of water present 
B)  [C2H3O2−] 
C)  [HC2H3O2] 
D)  the ratio of [C2H3O2−]/[HC2H3O2]

Question 5

Which of the following solutions will require the most NaOH in a titration experiment?

Accepted Answer

A)  25 mL of 0.5 M HCl 
B)  25 mL of 0.5 M HCOOH 
C)  25 mL of 0.5 M HC2H3O2 
D)  They all require the same amount. 
A)  25 mL of 0.5 M HCl 
B)  25 mL of 0.5 M HCOOH 
C)  25 mL of 0.5 M HC2H3O2 
D)  They all require the same amount.

Question 6

Which of the following can be characterized as a strong acid?

Accepted Answer

A)  HNO3 
B)  H2SO4 
C)  both HNO3 and H2SO4 
D)  neither HNO3 or H2SO4 
A)  HNO3 
B)  H2SO4 
C)  both HNO3 and H2SO4 
D)  neither HNO3 or H2SO4

Question 7

What is the concentration of hydronium ions in pure water at room temperature?

Accepted Answer

A)  1.0 × 10−14 M 
B)  1.0 × 10−7 M 
C)  1.0 × 107 M 
D)  1.0 × 1014 M 
A)  1.0 × 10−14 M 
B)  1.0 × 10−7 M 
C)  1.0 × 107 M 
D)  1.0 × 1014 M

Question 8

A student doing a titration of HNO3 with sodium hydroxide wants to use Clayton yellow as an indicator. Clayton yellow changes color at pH = 12.7. Which of the following will be true of this experiment?

Accepted Answer

A)  The concentration of HNO3 reported will be too high. 
B)  The concentration of HNO3 reported will be too low. 
C)  The concentration of HNO3 will be reported correctly. 
D)  The experiment cannot be done at all. 
A)  The concentration of HNO3 reported will be too high. 
B)  The concentration of HNO3 reported will be too low. 
C)  The concentration of HNO3 will be reported correctly. 
D)  The experiment cannot be done at all.

Question 9

Which of the following buffers is present in human blood?

Accepted Answer

A)  H2CO3/HCO3− 
B)  H2PO4−/HPO42− 
C)  both H2CO3/HCO3- and H2PO4-/HPO42- 
D)  none of these 
A)  H2CO3/HCO3− 
B)  H2PO4−/HPO42− 
C)  both H2CO3/HCO3- and H2PO4-/HPO42- 
D)  none of these

Question 10

The pKa of hydrocyanic acid is 9.31. What is the Ka of hydrocyanic acid?

Accepted Answer

A)  1.3 × 10−24 
B)  1.3 × 10−10 
C)  4.9 × 10−10 
D)  2.0 × 109 
A)  1.3 × 10−24 
B)  1.3 × 10−10 
C)  4.9 × 10−10 
D)  2.0 × 109

Question 11

A solution has a pH of 5.4. What is its pOH?

Accepted Answer

A)  -8.6 
B)  -5.4 
C)  5.4 
D)  8.6 
A)  -8.6 
B)  -5.4 
C)  5.4 
D)  8.6

Question 12

What are the two acids in the following reaction? NH4+(aq) + HPO42− ⇋ NH3 + H2PO4−

Accepted Answer

A)  NH4+ and HPO42− 
B)  NH4+ and NH3 
C)  HPO42− and H2PO4− 
D)  NH4+ and H2PO4− 
A)  NH4+ and HPO42− 
B)  NH4+ and NH3 
C)  HPO42− and H2PO4− 
D)  NH4+ and H2PO4−

Question 13

Consider the following hypothetical acid-base reaction. A(aq) + B(aq) ⇋ C(aq) + D(aq)
(weaker acid + weaker base ⇋ stronger acid + stronger base)
Which of the following statements is true of this reaction?

Accepted Answer

A)  The position of the equilibrium favors the forward reaction. 
B)  The position of the equilibrium favors the reverse reaction. 
C)  Neither the forward nor the reverse reaction is favored at equilibrium. 
D)  The position of equilibrium cannot be predicted from the given data. 
A)  The position of the equilibrium favors the forward reaction. 
B)  The position of the equilibrium favors the reverse reaction. 
C)  Neither the forward nor the reverse reaction is favored at equilibrium. 
D)  The position of equilibrium cannot be predicted from the given data.

Question 14

The pKa of HEPES is 7.55. What is the pH of a buffer prepared by mixing 200.0 mL of 0.20 M HEPES in its acid form with 100.0 mL of 0.20 M HEPES in its basic form?

Accepted Answer

A)  6.55 
B)  7.25 
C)  7.85 
D)  8.55 
A)  6.55 
B)  7.25 
C)  7.85 
D)  8.55

Question 15

Which of the following solutions will require the most NaOH in a titration experiment?

Accepted Answer

A)  25 mL of 0.500 M HCOOH 
B)  25 mL of 0.500 M H2SO4 
C)  25 mL of 0.500 M H3PO4 
D)  25 mL of 0.500 M HCl 
A)  25 mL of 0.500 M HCOOH 
B)  25 mL of 0.500 M H2SO4 
C)  25 mL of 0.500 M H3PO4 
D)  25 mL of 0.500 M HCl

Question 16

An acetic acid solution has a pH of 5.80. What is its [H3O+]?

Accepted Answer

A)  1.6 × 10−20 M 
B)  6.3 × 10−9 M 
C)  1.6 × 10−6 M 
D)  6.3 × 105 M 
A)  1.6 × 10−20 M 
B)  6.3 × 10−9 M 
C)  1.6 × 10−6 M 
D)  6.3 × 105 M

Question 17

Which of the following is the net ionic equation for the reaction of magnesium oxide (MgO) with the strong acid HCl?

Accepted Answer

A)  2HCl(aq) + MgO(s) → MgCl2(aq) + H2O(l) 
B)  2H3O+(aq) + MgO(s) → 3H2O(l) + Mg2+(aq) 
C)  2H3O+(aq) + Cl−(aq) + Mg2+(aq) + O2−(aq) → Mg2+(aq) + Cl−(aq) + 3H2O(l) 
D)  2OH−(aq) + Cl−(aq) + Mg2+(aq) → Mg2+(aq) + Cl−(aq) + O2−(aq) + H2O(l) 
A)  2HCl(aq) + MgO(s) → MgCl2(aq) + H2O(l) 
B)  2H3O+(aq) + MgO(s) → 3H2O(l) + Mg2+(aq) 
C)  2H3O+(aq) + Cl−(aq) + Mg2+(aq) + O2−(aq) → Mg2+(aq) + Cl−(aq) + 3H2O(l) 
D)  2OH−(aq) + Cl−(aq) + Mg2+(aq) → Mg2+(aq) + Cl−(aq) + O2−(aq) + H2O(l)

Question 18

In a particular titration experiment, a 25.0-mL sample of an unknown diprotic acid required 30.0 mL of 0.200 M NaOH for the end point to be reached. What is the concentration of the acid?

Accepted Answer

A)  0.120 M 
B)  0.167 M 
C)  0.240 M 
D)  0.333 M 
A)  0.120 M 
B)  0.167 M 
C)  0.240 M 
D)  0.333 M

Question 19

Which of the following is the Brønsted-Lowry definition of an acid?

Accepted Answer

A)  a hydroxide ion acceptor 
B)  a proton acceptor 
C)  a proton donor 
D)  none of these 
A)  a hydroxide ion acceptor 
B)  a proton acceptor 
C)  a proton donor 
D)  none of these

Question 20

Which of the following is the conjugate acid of HPO42−?

Accepted Answer

A)  H3PO4 
B)  H2PO4− 
C)  PO43− 
D)  H3O+ 
A)  H3PO4 
B)  H2PO4− 
C)  PO43− 
D)  H3O+

Exam 8: Acids and Bases

A sodium hydroxide solution has a pH of 11.40. What is its [H3O+]?

Which of the following acids is found in gastric fluid?

A solution has a pOH of 7.4. What is its pH?

Which of the following must be increased in order to decrease the buffer capacity of a buffer made using acetic acid and sodium acetate?

Which of the following solutions will require the most NaOH in a titration experiment?

Which of the following can be characterized as a strong acid?

What is the concentration of hydronium ions in pure water at room temperature?

A student doing a titration of HNO3 with sodium hydroxide wants to use Clayton yellow as an indicator. Clayton yellow changes color at pH = 12.7. Which of the following will be true of this experiment?

Which of the following buffers is present in human blood?

The pKa of hydrocyanic acid is 9.31. What is the Ka of hydrocyanic acid?

A solution has a pH of 5.4. What is its pOH?

What are the two acids in the following reaction? NH4+(aq) + HPO42− ⇋ NH3 + H2PO4−

Consider the following hypothetical acid-base reaction. A(aq) + B(aq) ⇋ C(aq) + D(aq) (weaker acid + weaker base ⇋ stronger acid + stronger base) Which of the following statements is true of this reaction?

The pKa of HEPES is 7.55. What is the pH of a buffer prepared by mixing 200.0 mL of 0.20 M HEPES in its acid form with 100.0 mL of 0.20 M HEPES in its basic form?

Which of the following solutions will require the most NaOH in a titration experiment?

An acetic acid solution has a pH of 5.80. What is its [H3O+]?

Which of the following is the net ionic equation for the reaction of magnesium oxide (MgO) with the strong acid HCl?

In a particular titration experiment, a 25.0-mL sample of an unknown diprotic acid required 30.0 mL of 0.200 M NaOH for the end point to be reached. What is the concentration of the acid?

Which of the following is the Brønsted-Lowry definition of an acid?

Which of the following is the conjugate acid of HPO42−?

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A sodium hydroxide solution has a pH of 11.40. What is its [H₃O⁺]?

A student doing a titration of HNO₃ with sodium hydroxide wants to use Clayton yellow as an indicator. Clayton yellow changes color at pH = 12.7. Which of the following will be true of this experiment?

The pK_a of hydrocyanic acid is 9.31. What is the K_a of hydrocyanic acid?

What are the two acids in the following reaction? NH₄⁺(aq) + HPO₄²⁻ ⇋ NH₃ + H₂PO₄⁻

The pK_a of HEPES is 7.55. What is the pH of a buffer prepared by mixing 200.0 mL of 0.20 M HEPES in its acid form with 100.0 mL of 0.20 M HEPES in its basic form?

An acetic acid solution has a pH of 5.80. What is its [H₃O⁺]?

Which of the following is the conjugate acid of HPO₄²⁻?