Chemistry Chapter 14 Study

An unknown weak acid with a concentration of 0.090 M has a pH of 1.80. What is the Ka of the weak acid?

0.0034

What is the percent ionization of H₂NNH₂ in a solution with a concentration of a 0.500 M? (Kb = 1.3 × 10⁻⁶)

0.16 %

The pH of a 0.0040 M solution of Ca(OH)₂ is

11.90

The pOH of a 0.0250 M solution of HCl is

12.398

How many milliliters of 0.20 M HCl is required to neutralize 50.0 mL of 0.80 M NaOH?

2.0 × 10² mL or 200mL

What is the pH of a 0.500 M solution of the salt formed by the reaction between the acid HF (pKa = 3.17) and the base NH₃ (pKb = 4.74)?

6.22

The weak acid HY is much stronger than weak acid HX. Which one of the following statements is true? A) Y⁻ is a stronger base than X⁻. B) Y⁻ is a weaker base than X⁻. C) Y⁻ and X⁻ will be bases of approximately the same strength.

B) Y⁻ is a weaker base than X⁻.

Which one of the following correctly shows the weak acid equilibrium for trichloroacetic acid, CCl₃COOH? A) CCl₃COOH (aq) ⇌ CCl₃CO⁺ (aq) + OH⁻ (aq) B) CCl₃COOH (aq) + H₂O (l) ⇌ CCl₃COOH₂⁺ (aq) + OH⁻ (aq) C) CCl₃COOH (aq) + H₂O (l) ⇌ CCl₃COO⁻ (aq) + H₃O⁺ (aq) D) CCl₃COOH (aq) + H₂O (l) ⇌ CCl₃CO(OH)₂⁻ (aq) + H⁺ (aq)

C) CCl₃COOH (aq) + H₂O (l) ⇌ CCl₃COO⁻ (aq) + H₃O⁺ (aq)

3 NaOH(aq) + C₆H₈O₇(aq) ⇌ Na₃C₆H₅O₇(aq) + 3 H₂O(l) Step 1: Evaluate the question. How many moles of aqueous sodium hydroxide (NaOH) will react to completely neutralize one mole of aqueous citric acid (C₆H₈O₇)? A) 1 B) 2 C) 3 D) 4 E) 5

C) 3

The pOH of a 0.300 M solution of NaOH is

0.523

Given that K(eq) = K(sp), calculate concentration of the aqueous cation formed at equilibrium when excess solid CuCl is placed in water if K(eq) = 1.00 × 10⁻⁶.

1.00 × 10⁻³ M

What is Kb for the conjugate base of HCN (Ka = 4.9 × 10⁻¹⁰)?

2.0 × 10⁻⁵

The iodate ion has a number of insoluble compounds. The Ksp for AgIO₃ is 3.0 x 10⁻⁸ and the Ksp for La(IO₃)₃ is 7.5 x 10⁻¹². The solubility in an 0.200 M solution of NaIO₃ of AgIO₃ is 1.5 × 10⁻⁷ and the solubility of La(IO₃)₃ is 9.4 × 10⁻¹⁰. Which compound is more soluble? A) AgIO₃ B) La(IO₃)₃

A) AgIO₃

For which of the following aqueous solutions will a decrease of pH increase the solubility? A) CaCO₃ B) PbCl₂ C) CuBr D) AgCl

A) CaCO₃

The conjugate acid of H₂PO₄⁻ is A) H₃PO₄ B) HPO₄²⁻ C) PO₄³⁻ D) H₂PO₄

A) H₃PO₄

Rank the following in order of most acidic to least acidic. Solution X pH = 8.50 Solution Y pOH = 4.30 Solution Z [OH-] = 4.2 x 10-9M A) Z >>Y B) Y >>Z C) Y>Z>X D) X > Y>Z

A) Z > X > Y

The value of Kw increases as temperature increases. Is the autoionization of water exothermic or endothermic? A) endothermic B) exothermic

A) endothermic

Calculate the pH when 45.0 mL of 0.200 M HBr is mixed with 30.0 mL of 0.400 M CH₃NH₂ (Kb = 4.4 × 10⁻⁴).

10.16

The pH of an acidic solution is 4.67. What is [H⁺]?

2.1 × 10⁻⁵ M

What is the pH of a 0.0380 M solution of HONH₃Cl (Kb of HONH₂ is 1.1 × 10⁻⁸)?

3.73

A neutral solution of water at a particular temperature has a concentration of OH⁻ of 2.3 × 10⁻⁷ M. What is Kw at this temperature?

5.3 × 10⁻¹⁴

At 15°C, the value of Kw is 4.5 × 10⁻¹⁵. What is the equilibrium concentration of OH⁻ at this temperature?

6.7 × 10⁻⁸ M

What is the pH of a 0.320 M solution of Ca(NO₂)₂ (Ka of HNO₂ is 4.5 × 10⁻⁴)?

8.58

Determine the molar solubility for Ag₂CrO₄ (Ksp = 1.2 × 10⁻¹²).

I - 0 0 C - +2x +x E - +2x +x Ksp = [2x]^2[x] = 1.2*10^-12 6.7*10^-5

The concentration of the hydronium ion in an aqueous solution at 25 °C is 0.0092 M. What is the concentration of the hydroxide ion?

1.1 × 10⁻¹² M

In an aqueous solution at 25°C, if [H₃O⁺] = 9.0 × 10⁻⁴ M, then [OH⁻] is:

1.1 × 10⁻¹¹ M

The H⁺ concentration in an aqueous solution at 25 °C is 9.5 × 10⁻⁶. What is [OH⁻]?

1.1 × 10⁻⁹ M

The OH⁻ concentration in an aqueous solution at 25 °C is 7.5 × 10⁻³. What is [H⁺]?

1.3 × 10⁻¹² M

An unknown weak acid with a concentration of 0.440 M has a pH of 5.600. What is the Ka of the weak acid?

1.43 × 10⁻¹¹

The iodate ion has a number of insoluble compounds. The Ksp for AgIO₃ is 3.0 x 10⁻⁸ and the Ksp for La(IO₃)₃ is 7.5 x 10⁻¹². What is the solubility of AgIO₃ in a 0.200 M solution of NaIO₃?

1.5 × 10⁻⁷ M

The iodate ion has a number of insoluble compounds. The Ksp for AgIO₃ is 3.0 x 10⁻⁸ and the Ksp for La(IO₃)₃ is 7.5 x 10⁻¹². What is the solubility of AgIO₃ in aqueous solution?

1.7 × 10⁻⁴ M

What is the pH of a 0.400 M solution of HF (Ka = 6.8 × 10⁻⁴)?

1.79

What is the solubility of MgCO₃ in water? (Ksp of MgCO₃ is 3.5 × 10⁻⁸)

1.9 × 10⁻⁴ M

3 NaOH(aq) + C₆H₈O₇(aq) ⇌ Na₃C₆H₅O₇(aq) + 3 H₂O(l) Step 3: Calculate the volume of titrant required to reach the endpoint. Calculate the volume in mL of a 0.200 M NaOH solution needed to neutralize 345 mL of 0.0333 M C₆H₈O₇ standard solution.

172 mL

What is Ka for the conjugate acid of CH₃NH₂ (Kb = 4.4 × 10⁻⁴)?

2.3 × 10⁻¹¹

What is the percent ionization in a 0.300 M solution of formic acid (HCOOH) (Ka = 1.78 × 10⁻⁴)?

2.44 %

The pH of a 0.0023 M solution of HNO₃ is

2.64

What is [H⁺] in a 0.230 M solution of acrylic acid, CH₂CHCOOH (Ka = 3.16 × 10⁻⁵)?

2.70 × 10⁻³

An unknown weak base with a concentration of 0.0910 M has a pH of 11.70. What is the Kb of this base?

2.9 × 10⁻⁴

In a titration of 36.0 mL of a 0.250 M solution of a triprotic acid H₃PO₄ (phosphoric acid) with 0.600 M Ca(OH)₂, how many mL of base are required to reach the third equivalence point?

22.5 mL

The pH of a basic solution is 10.15. What is pOH?

3.85

What is the [OH⁻] of a 1.40 M solution of pyridine (C₅H₅N, Kb = 1.70 × 10⁻⁹)?

4.88 × 10⁻⁵ M

The iodate ion has a number of insoluble compounds. The Ksp for AgIO₃ is 3.0 x 10⁻⁸ and the Ksp for La(IO₃)₃ is 7.5 x 10⁻¹². What is the solubility of La(IO₃)₃ in aqueous solution?

7.3 × 10⁻⁴ M

The pH of a basic solution is 8.11. What is [H⁺]?

7.8 × 10⁻⁹ M

The pOH of an acidic solution is 10.05. What is [OH⁻]?

8.9 × 10⁻¹¹ M

You have 0.500 L of an 0.250 M acetate buffer solution (i.e. [HC₂H₃O₂] + [C₂H₃O₂⁻] = 0.250 M) at pH 3.50. How many mL of 1.000 M NaOH must you add in order to change the pH to 5.25? Acetic acid has a pKa of 4.74.

89 mL

What is the pH of a 0.300 M solution of aniline (C₆H₅NH₂, Kb = 4.3 × 10⁻¹⁰)?

9.06

The solubility of Ag₃PO₄ in water at 25 °C is 4.3 × 10⁻⁵ M. What is Ksp for Ag₃PO₄?

9.2 × 10⁻¹⁷

The iodate ion has a number of insoluble compounds. The Ksp for AgIO₃ is 3.0 x 10⁻⁸ and the Ksp for La(IO₃)₃ is 7.5 x 10⁻¹². What is the solubility of La(IO₃)₃ in a 0.200 M solution of NaIO₃?

9.4 × 10⁻¹⁰ M

Which of the following combinations can be used to make a buffer? (Assume equal volumes are used.) A) 0.50 M HF and 0.20 M NaF B) 0.50 M HF and 0.50 M NaOH C) 0.50 M HF and 0.50 M HCl D) 0.50 M HCl and 0.50 M NaF

A) 0.50 M HF and 0.20 M NaF

The approximate pKa values of several acids are given in the table below. In which of the following acid-base reactions will both the forward and reverse reactions be equally favored? A) NH4+ (aq) + CN-(aq) = NH3(aq) + HCN(aq) ~pka 5 B) CH3NH3+(aq) + CH3CO2 (aq) = CH3NH2(aq) + CH3CO2H(aq) 5 9 Acid C5H5NH+ CH3CO2H NH4+ HCN C6H5OH HCO3 CH3NH3+ H2O CH3OH 9 10 C) CsHsNH+(aq) + HO-(aq) = CsHsN(aq) + H2O(1) 10 D) CH3OH(aq) + CO32-(aq) = CH3O-(aq) + HCO3-(aq) 11 16 16 E) HON(aq) + CH30-(aq) = CN-(aq) + CH3OH(aq)

A) NH₄⁺(aq) + CN⁻(aq) ⇌ NH₃(aq) + HCN(aq)

Which one of the following 1.0 M solutions would have the highest pH? ΗΝΟ2 4.5 x 10^-4 C.H.COOH 6.3 x 10^-5 HCNO 3.5 x 10-4 HNO 6.8 x 10^-4 A) HNO2 B) C₆H₅COOH C) HCNO D) HF

B) C₆H₅COOH

Which one of the following correctly shows the equilibrium for the weak base quinoline, C₉H₇N? A) C₉H₇N (aq) + 2 H₂O (l) ⇌ C₉H₇NH₂⁺ (aq) + 2 OH⁻ (aq) B) C₉H₇N (aq) + H₂O (l) ⇌ C₉H₇NH⁺ (aq) + OH⁻ (aq) C) C₉H₇N (aq) + H₂O ⇌ C₉H₆N (aq) + H₃O⁺ (aq) D) C₉H₇N (aq) + H₂O (l) ⇌ C₉H₈NO (aq) + H₃O⁺ (aq)

B) C₉H₇N (aq) + H₂O (l) ⇌ C₉H₇NH⁺ (aq) + OH⁻ (aq)

Consider the reaction below. Which species are conjugate acid/base pairs? HSO₃⁻ (aq) + HCN (aq) ⇌ H₂SO₃ (aq) + CN⁻ (aq) A) HSO₃⁻, CN⁻ B) HSO₃⁻, H₂SO₃ C) H₂SO₃, CN⁻ D) HCN, H₂SO₃

B) HSO₃⁻, H₂SO₃

The iodate ion has a number of insoluble compounds. The Ksp for AgIO₃ is 3.0 x 10⁻⁸ and the Ksp for La(IO₃)₃ is 7.5 x 10⁻¹². The solubility of AgIO₃ is 1.7 × 10⁻⁴ and the solubility of La(IO₃)₃ is 7.3 × 10⁻⁴. Which compound is more soluble? A) AgIO₃ B) La(IO₃)₃

B) La(IO₃)₃

At the equivalence point for the titration of HCN with KOH, the pH is expected to be A) 7 B) greater than 7 C) less than 7

B) greater than 7

The solubility of a salt refers to A) the concentration of all ions in the solution. B) how much of a salt will dissolve. C) the equilibrium constant associated with a solubility equilibrium. D) how many ions a salt dissociates into.

B) how much of a salt will dissolve.

A solution has a pOH of 7.84. This tells us A) the solution is very acidic. B) the solution is only slightly acidic. C) the solution is only slightly basic. D) The solution is very basic.

B) the solution is only slightly acidic.

3 NaOH(aq) + C₆H₈O₇(aq) ⇌ Na₃C₆H₅O₇(aq) + 3 H₂O(l) Step 4: Knowledge check. Based on the fact that NaOH is a strong base and C₆H₈O₇ is a weak acid, how would you describe the pH of the solution at the endpoint, where moles of base = 3 times the moles of acid? A) strongly basic pH B) weakly basic pH C) neutral pH D) weakly acidic pH E) strongly acidic pH

B) weakly basic pH

Which of the following statements is true? A) A buffer forms when any acid or base are mixed together. B) A buffer forms when a strong acid is mixed with a weak acid. C) A buffer forms when a conjugate weak acid/weak base pair are mixed together. D) A buffer forms when a weak acid is mixed with a weak base.

C) A buffer forms when a conjugate weak acid/weak base pair are mixed together.

Which one of the following statements is true? A) A solution with a pH of 3.40 will have a higher concentration of hydroxide ions than hydronium ions. B) A solution with a pOH of 2.10 is very acidic. C) A solution with a pH of 8.20 is only slightly basic. D) A solution with a pOH of 13.20 is very basic.

C) A solution with a pH of 8.20 is only slightly basic.

Which one of the following 1.0 M solutions would have the lowest pH? Weak Base Kb C5H5N 1.7 x 10-9 HONH2 1.1 x 10-8 CeHsNH2 4.3 x 10-10 H2NNH2 1.3 x 10-6 A) CBHN B) HONH2 C) C₆H₅NH₂

C) C₆H₅NH₂

Consider the table of weak bases below. Which of the following 1.0 M solutions would have the lowest pH? A) C₅H₅NH⁺ B) HONH₃⁺ C) C₆H₅NH₃⁺ D) H₂NNH₃⁺

C) C₆H₅NH₃⁺

Which of the following would be the acid equilibrium equation for HONH₃Cl? A) HONH₃⁺ (aq) ⇌ NH₃ (aq) + OH⁻(aq) B) HONH₃Cl (aq) ⇌ HONH₃⁺ (aq) + Cl⁻ (aq) C) HONH₃⁺ (aq) + H₂O (l) ⇌ HONH₂ (aq) + H₃O⁺ (aq) D) HCl (aq) ⇌ H⁺ (aq) + Cl⁻ (aq)

C) HONH₃⁺ (aq) + H₂O (l) ⇌ HONH₂ (aq) + H₃O⁺ (aq)

Which of the following is the correct expression for Ksp for Zn₃(PO₄)₂?

C) Ksp = [Zn2+]3 [PO43-]2

Which acid-base definition classifies an acid as an electron-pair acceptor? A) Arrhenius B) Bronsted-Lowry C) Lewis

C) Lewis

Which one of the following titrations is expected to have a pH < 7 at the equivalence point? A) HNO₃ titrated with LiOH B) HNO₂ titrated with KOH C) NaNO₂ titrated with HBr D) NaNO₃ titrated with HBr

C) NaNO₂ titrated with HBr

Rank the following in order of most acidic to least acidic. Solution X pH = 6.50 Solution Y pOH = 10.30 Solution Z [OH-] = 4.2 x 10-9 M A) Z > Y>X B) Y>X>z C)Y>Z>X D) X > Y>Z

C) Y > Z > X

At the equivalence point for the titration of NH₃ with HBr, the pH is expected to be A) 7 B) greater than 7 C) less than 7

C) less than 7

Which of the following combinations can be used to make a buffer? (Assume equal volumes are used.) A) 0.30 M HCN and 0.30 M HBr B) 0.30 M HCN and 0.15 M HBr C) 0.30 M HCN and 0.30 M NaOH D) 0.30 M HCN and 0.15 M NaOH

D) 0.30 M HCN and 0.15 M NaOH

The approximate pKa values of several acids are given in the table below. In which of the following acid-base reactions will the forward reaction be favored? A) CH NH, (aq) + CN(aq) = CH NH, (aq) + HCN(aq) B) H,0(1) + CH 0(aq) = HO(aq) + CH,OH(aq) Acid C6H5NH+ CH3CO2H NH4+ HCN C6H5OH HCO3 CH3NH3+ H20 CH3OH 5 9 9 10 C) HO(1) + CHO(aq)=HO(aq) + CH, OH(aq) 10 11 D) CH CO,H(aq) + CH NH(aq)=CH-CO, (aq) +CH NH,*(aq) 16 16 E) HCN(aq) + NH,(aq)=CN(aq) + NH *(aq)

D) CH₃CO₂H(aq) + CH₃NH₂(aq) ⇌ CH₃CO₂⁻(aq) + CH₃NH₃⁺(aq)

Consider the reaction below. Which species is(are) the Brønsted-Lowry base(s)? HCO₃⁻ (aq) + F⁻ (aq) ⇌ CO₃²⁻ (aq) + HF (aq) A) F⁻, HF B) HCO₃⁻, F⁻ C) CO₃²⁻, HF D) CO₃²⁻, F⁻

D) CO₃²⁻, F⁻

Which of the following would be the base equilibrium equation for CsClO? A) CsClO (aq) ⇌ Cs⁺ (aq) + ClO⁻ (aq) B) ClO⁻ (aq) + H₂O (l) ⇌ ClOOH (aq) + H₃O⁺ (aq) C) ClO⁻ (aq) + H₂O (l) ⇌ H₂ClO₂ (aq) D) ClO⁻ (aq) + H₂O (l) ⇌ HClO (aq) + OH⁻ (aq)

D) ClO⁻ (aq) + H₂O (l) ⇌ HClO (aq) + OH⁻ (aq)

Which of the following is a conjugate acid/base pair? A) H₂O, NH₃ B) NH₄⁺, H₃O⁺ C) H₃O⁺, NH₃ D) H₃O⁺, H₂O

D) H₃O⁺, H₂O

3 NaOH(aq) + C₆H₈O₇(aq) ⇌ Na₃C₆H₅O₇(aq) + 3 H₂O(l) Step 2: Design a problem-solving strategy. Which equation will be most helpful for solving this problem? A) PV = nRT B) M₁V₁ = M₂V₂ C) pH = -log[H⁺] D) M₁V₁/n₁ = M₂V₂/n₂

D) M₁V₁/n₁ = M₂V₂/n₂

A solution has a pH of 13.20. We can conclude that A) the solution is very acidic. B) the solution is only slightly acidic. C) the solution is only slightly basic. D) The solution is very basic.

D) The solution is very basic.

NaOH is a Brønsted-Lowry base because A) it is a polar molecule. B) it can dissolve in water. C) it is a hydroxide donor. D) it is a proton acceptor.

D) it is a proton acceptor.

Determine the molar solubility for Sr₃(PO₄)₂ (Ksp = 1.0 × 10⁻³¹).

I - 0 0 C - +3x +2x E - +3x +2x Ksp = [3x]^3[2x]^2 = 1*10^-31 2.5*10^-7

Determine the molar solubility for Cr(OH)₃ (Ksp = 6.3 × 10⁻³¹).

I - 0 0 C - +x +3x E - +x +3x Ksp = [x][3x]^3 = 6.3*10^-32 1.2*10^-8