Question 1

Write a net ionic equation for the reaction that occurs when a small amount of nitric acid is added to a NaNO2/HNO2 buffer.

Accepted Answer

H<sup>+</sup> + NO<s

Question 2

An environmental chemist obtained a 200.mL sample of lake water believed to be contaminated with a single monoprotic strong acid.Titrating this sample with a 0.0050 M NaOH(aq)required 7.3 mL of the NaOH solution to reach the endpoint.What is the concentration of H+ in the lake?

Accepted Answer

1.8 * 10<s

Question 3

Which one of the following combinations cannot function as a buffer solution?

Accepted Answer

A) HCN and KCN 
B) NH3 and (NH4)2SO4 
C) HNO3 and NaNO3 
D) HF and NaF 
E) HNO2 and NaNO2 
A) HCN and KCN 
B) NH3 and (NH4)2SO4 
C) HNO3 and NaNO3 
D) HF and NaF 
E) HNO2 and NaNO2

Question 4

A mixture made from 10 mL of 1 M HCl and 20 mL of 1 M CH3COONa would be classified as a buffer solution.

Accepted Answer

A) True 
 B)False

Question 5

Calculate the silver ion concentration in a saturated solution of silver(I)carbonate (Ksp = 8.1 *10-12).

Accepted Answer

A) 5.0 * 10-5 M 
B) 2.5 * 10-4 M 
C) 1.3 * 10-4 M 
D) 2.0 * 10-4 M 
E) 8.1 * 10-4 M 
A) 5.0 * 10-5 M 
B) 2.5 * 10-4 M 
C) 1.3 * 10-4 M 
D) 2.0 * 10-4 M 
E) 8.1 * 10-4 M

Question 6

NaCl is added slowly to a solution that is 0.010 M each in Cu+, Ag+, and Au+.The Ksp's for CuCl, AgCl, and AuCl are 1.9 * 10-7, 1.8 * 10-10, and 2.0 * 10-13, respectively.Which compound will precipitate first?

Accepted Answer

The answer of NaCl is added slowly to a solution...

Question 7

Which response has both answers correct? Will a precipitate form when 250 mL of 0.33 M Na2CrO4 are added to 250 mL of 0.12 M AgNO3? [Ksp(Ag2CrO4)= 1.1 *10-12] What is the concentration of the silver ion remaining in solution?

Accepted Answer

A) Yes, [Ag+] = 2.9 * 10-6 M. 
B) Yes, [Ag+] = 0.060 M. 
C) Yes, [Ag+] = 1.3 * 10-4 M. 
D) No, [Ag+] = 0.060 M. 
E) No, [Ag+] = 0.105 M. 
A) Yes, [Ag+] = 2.9 * 10-6 M. 
B) Yes, [Ag+] = 0.060 M. 
C) Yes, [Ag+] = 1.3 * 10-4 M. 
D) No, [Ag+] = 0.060 M. 
E) No, [Ag+] = 0.105 M.

Question 8

In which one of the following solutions will acetic acid have the greatest percent ionization?

Accepted Answer

A) 0.1 M CH3COOH 
B) 0.1 M CH3COOH dissolved in 0.1 M HCl 
C) 0.1 M CH3COOH dissolved in 0.2 M HCl 
D) 0.1 M CH3COOH plus 0.1 M CH3COONa 
E) 0.1 M CH3COOH plus 0.2 M CH3COONa 
A) 0.1 M CH3COOH 
B) 0.1 M CH3COOH dissolved in 0.1 M HCl 
C) 0.1 M CH3COOH dissolved in 0.2 M HCl 
D) 0.1 M CH3COOH plus 0.1 M CH3COONa 
E) 0.1 M CH3COOH plus 0.2 M CH3COONa

Question 9

At 25 °C, the base ionization constant for NH3 is 1.8 * 10-5. Determine the percentage ionization of a 0.150 M solution of ammonia at 25 °C.

Accepted Answer

The answer of At 25 °C, the base ionization constant...

Question 10

An environmental chemist obtained a 200.mL sample of lake water believed to be contaminated with a single monoprotic strong acid.Titrating this sample with a 0.0050 M NaOH(aq)required 7.3 mL of the NaOH solution to reach the endpoint.If the size of the lake can be approximated as 1.1 km long by 2.3 km wide, and has an average depth of 10.m, estimate how many moles of the strong acid are present in the lake?

Accepted Answer

4.6 * 10<s

Question 11

Solid sodium iodide is slowly added to a solution that is 0.0050 M Pb2+ and 0.0050 M Ag+.[Ksp (PbI2)= 1.4 * 10-8; Ksp (AgI)= 8.3 * 10-17] Calculate the Ag+ concentration when PbI2 just begins to precipitate.

Accepted Answer

5.0 * 10<s

Question 12

The solubility product for calcium phosphate is Ksp = 1.3 *10-26. What is the molar solubility of calcium phosphate?

Accepted Answer

A) 1.3 * 10-26 M 
B) 1.5 * 10-7 M 
C) 2.6 * 10-6 M 
D) 4.6 * 10-6 M 
E) 6.6 * 10-6 M 
A) 1.3 * 10-26 M 
B) 1.5 * 10-7 M 
C) 2.6 * 10-6 M 
D) 4.6 * 10-6 M 
E) 6.6 * 10-6 M

Question 13

Write a net ionic equation for the reaction that occurs when a small amount of hydrochloric acid is added to a buffer solution containing NH4Cl and NH3.

Accepted Answer

H<sup>+</sup> + NH<s

Question 14

A sample of rainwater collected near a lead smelter is analyzed for acid content.Experiments show that a 100.mL sample of the rainwater is neutralized by 22.4 milliters of 0.0122 M NaOH.Assuming that the acid present is sulfurous acid, which resulted from the reaction of SO2 with water, what is the molarity of acid in the rainwater?

Accepted Answer

1.37 * 10<

Question 15

A saturated sodium carbonate solution at 0°C contains 7.1 g of dissolved sodium carbonate per 100.mL of solution. The solubility product constant for sodium carbonate at this temperature is

Accepted Answer

A) 1.2 
B) 0.30 
C) 3.0 * 10-4 
D) 0.90 
E) 1.2 * 10-3 
A) 1.2 
B) 0.30 
C) 3.0 * 10-4 
D) 0.90 
E) 1.2 * 10-3

Question 16

Will a precipitate (ppt)form when 300.mL of 5.0 * 10-5 M AgNO3 are added to 200.mL of 2.5 * 10-7 M NaBr? Answer yes or no, and identify the precipitate if there is one.

Accepted Answer

A) Yes, the ppt is AgNO3(s). 
B) Yes, the ppt is AgBr(s). 
C) Yes, the ppt is NaBr(s). 
D) Yes, the ppt is NaNO3(s). 
E) No, a precipitate will not form. 
A) Yes, the ppt is AgNO3(s). 
B) Yes, the ppt is AgBr(s). 
C) Yes, the ppt is NaBr(s). 
D) Yes, the ppt is NaNO3(s). 
E) No, a precipitate will not form.

Question 17

Consider a buffer solution prepared from HOCl and NaOCl. Which is the net ionic equation for the reaction that occurs when NaOH is added to this buffer?

Accepted Answer

A) OH- + HOCl $\rarr$H2O + OCl- 
B) OH- + OCl- $\rarr$ HOCl + O2- 
C) Na+ + HOCl $\rarr$ NaCl + OH- 
D) H+ + HOCl $\rarr$ H2 + OCl- 
E) NaOH + HOCl $\rarr$ H2O + NaCl 
A) OH- + HOCl $\rarr$H2O + OCl- 
B) OH- + OCl- $\rarr$ HOCl + O2- 
C) Na+ + HOCl $\rarr$ NaCl + OH- 
D) H+ + HOCl $\rarr$ H2 + OCl- 
E) NaOH + HOCl $\rarr$ H2O + NaCl

Question 18

What mass of ammonium nitrate must be added to 350.mL of a 0.150 M solution of ammonia to give a buffer having a pH of 9.00? (Kb(NH3)= 1.8 * 10-5)

Accepted Answer

A) 7.6 g 
B) 2.4 g 
C) 5.4 g 
D) 11 g 
E) 3.3 g 
A) 7.6 g 
B) 2.4 g 
C) 5.4 g 
D) 11 g 
E) 3.3 g

Question 19

Will a precipitate form (yes or no)when 50.0 mL of 1.2 * 10-3 M Pb(NO3)2 are added to 50.0 mL of 2.0 * 10-4 M Na2S? If so, identify the precipitate.

Accepted Answer

A) Yes, the precipitate is PbS. 
B) Yes, the precipitate is NaNO3. 
C) Yes, the precipitate is Na2S. 
D) Yes, the precipitate is Pb(NO3)2. 
E) No, a precipitate will not form. 
A) Yes, the precipitate is PbS. 
B) Yes, the precipitate is NaNO3. 
C) Yes, the precipitate is Na2S. 
D) Yes, the precipitate is Pb(NO3)2. 
E) No, a precipitate will not form.

Question 20

Calculate the percent ionization of cyanic acid, Ka = 2.0 * 10-4, in a buffer solution that is 0.50 M HCNO and 0.10 M NaCNO.

Accepted Answer

A) 0.02% 
B) 0.10% 
C) 0.20% 
D) 2.0% 
E) 20% 
A) 0.02% 
B) 0.10% 
C) 0.20% 
D) 2.0% 
E) 20%

Exam 16: Acid-Base Equilibria and Solubility Equilibria

Write a net ionic equation for the reaction that occurs when a small amount of nitric acid is added to a NaNO2/HNO2 buffer.

An environmental chemist obtained a 200.mL sample of lake water believed to be contaminated with a single monoprotic strong acid.Titrating this sample with a 0.0050 M NaOH(aq)required 7.3 mL of the NaOH solution to reach the endpoint.What is the concentration of H+ in the lake?

Which one of the following combinations cannot function as a buffer solution?

A mixture made from 10 mL of 1 M HCl and 20 mL of 1 M CH3COONa would be classified as a buffer solution.

Calculate the silver ion concentration in a saturated solution of silver(I)carbonate (Ksp = 8.1 *10-12).

NaCl is added slowly to a solution that is 0.010 M each in Cu+, Ag+, and Au+.The Ksp's for CuCl, AgCl, and AuCl are 1.9 * 10-7, 1.8 * 10-10, and 2.0 * 10-13, respectively.Which compound will precipitate first?

Which response has both answers correct? Will a precipitate form when 250 mL of 0.33 M Na2CrO4 are added to 250 mL of 0.12 M AgNO3? [Ksp(Ag2CrO4)= 1.1 *10-12] What is the concentration of the silver ion remaining in solution?

In which one of the following solutions will acetic acid have the greatest percent ionization?

At 25 °C, the base ionization constant for NH3 is 1.8 * 10-5. Determine the percentage ionization of a 0.150 M solution of ammonia at 25 °C.

Solid sodium iodide is slowly added to a solution that is 0.0050 M Pb2+ and 0.0050 M Ag+.[Ksp (PbI2)= 1.4 * 10-8; Ksp (AgI)= 8.3 * 10-17] Calculate the Ag+ concentration when PbI2 just begins to precipitate.

The solubility product for calcium phosphate is Ksp = 1.3 *10-26. What is the molar solubility of calcium phosphate?

Write a net ionic equation for the reaction that occurs when a small amount of hydrochloric acid is added to a buffer solution containing NH4Cl and NH3.

A saturated sodium carbonate solution at 0°C contains 7.1 g of dissolved sodium carbonate per 100.mL of solution. The solubility product constant for sodium carbonate at this temperature is

Will a precipitate (ppt)form when 300.mL of 5.0 * 10-5 M AgNO3 are added to 200.mL of 2.5 * 10-7 M NaBr? Answer yes or no, and identify the precipitate if there is one.

Consider a buffer solution prepared from HOCl and NaOCl. Which is the net ionic equation for the reaction that occurs when NaOH is added to this buffer?

What mass of ammonium nitrate must be added to 350.mL of a 0.150 M solution of ammonia to give a buffer having a pH of 9.00? (Kb(NH3)= 1.8 * 10-5)

Will a precipitate form (yes or no)when 50.0 mL of 1.2 * 10-3 M Pb(NO3)2 are added to 50.0 mL of 2.0 * 10-4 M Na2S? If so, identify the precipitate.

Calculate the percent ionization of cyanic acid, Ka = 2.0 * 10-4, in a buffer solution that is 0.50 M HCNO and 0.10 M NaCNO.

Chemistry: The Study of Change

Atoms, Molecules, and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solution

Gases

Thermo-Chemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Chemistry in the Atmosphere

Entropy, Free Energy, and Equilibrium

Electrochemistry

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metal Chemistry and Coordination Compounds

Nuclear Chemistry

Organic Chemistry

Synthetic and Natural Organic Polymers

Filters

Write a net ionic equation for the reaction that occurs when a small amount of nitric acid is added to a NaNO₂/HNO₂ buffer.

An environmental chemist obtained a 200.mL sample of lake water believed to be contaminated with a single monoprotic strong acid.Titrating this sample with a 0.0050 M NaOH(aq)required 7.3 mL of the NaOH solution to reach the endpoint.What is the concentration of H⁺ in the lake?

A mixture made from 10 mL of 1 M HCl and 20 mL of 1 M CH₃COONa would be classified as a buffer solution.

Calculate the silver ion concentration in a saturated solution of silver(I)carbonate (K_sp = 8.1 *10^-12).

NaCl is added slowly to a solution that is 0.010 M each in Cu⁺, Ag⁺, and Au⁺.The K_sp's for CuCl, AgCl, and AuCl are 1.9 * 10^-7, 1.8 * 10^-10, and 2.0 * 10^-13, respectively.Which compound will precipitate first?

Which response has both answers correct? Will a precipitate form when 250 mL of 0.33 M Na₂CrO₄ are added to 250 mL of 0.12 M AgNO₃? [K_sp(Ag₂CrO₄)= 1.1 *10^-12] What is the concentration of the silver ion remaining in solution?

At 25 °C, the base ionization constant for NH₃ is 1.8 * 10^-5. Determine the percentage ionization of a 0.150 M solution of ammonia at 25 °C.

Solid sodium iodide is slowly added to a solution that is 0.0050 M Pb²⁺ and 0.0050 M Ag⁺.[K_sp (PbI₂)= 1.4 * 10^-8; K_sp (AgI)= 8.3 * 10^-17] Calculate the Ag⁺ concentration when PbI₂ just begins to precipitate.

The solubility product for calcium phosphate is K_sp = 1.3 *10^-26. What is the molar solubility of calcium phosphate?

Write a net ionic equation for the reaction that occurs when a small amount of hydrochloric acid is added to a buffer solution containing NH₄Cl and NH₃.

Will a precipitate (ppt)form when 300.mL of 5.0 * 10^-5 M AgNO₃ are added to 200.mL of 2.5 * 10^-7 M NaBr? Answer yes or no, and identify the precipitate if there is one.

What mass of ammonium nitrate must be added to 350.mL of a 0.150 M solution of ammonia to give a buffer having a pH of 9.00? (K_b(NH₃)= 1.8 * 10^-5)

Will a precipitate form (yes or no)when 50.0 mL of 1.2 * 10^-3 M Pb(NO₃)₂ are added to 50.0 mL of 2.0 * 10^-4 M Na₂S? If so, identify the precipitate.

Calculate the percent ionization of cyanic acid, K_a = 2.0 * 10^-4, in a buffer solution that is 0.50 M HCNO and 0.10 M NaCNO.