Question 1

Write the ion product expression for magnesium fluoride,MgF2.

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) 
  
A) 
  
B) 
  
C) 
  
D) 
  
E) 
  B

Question 2

A buffer is prepared by adding 100 mL of 0.50 M sodium hydroxide to 100 mL of 0.75 M propanoic acid.Is this a buffer solution,and if so,what is its pH?

Accepted Answer

A) It is a buffer,pH > pKa of propanoic acid. 
B) It is a buffer,pH a of propanoic acid. 
C) It is a buffer,pH = pKa of propanoic acid. 
D) It is a buffer,pH = pKb of sodium propanoate. 
E) Since sodium hydroxide is a strong base,this is not a buffer. 
A) It is a buffer,pH > pKa of propanoic acid. 
B) It is a buffer,pH a of propanoic acid. 
C) It is a buffer,pH = pKa of propanoic acid. 
D) It is a buffer,pH = pKb of sodium propanoate. 
E) Since sodium hydroxide is a strong base,this is not a buffer. A

Question 3

Formic acid is a monoprotic acid with a Ka value of 1.8 $\times$ 10-4 at 25°C.
a.Calculate the pH of a 0.200 mol L-1 solution of the acid,making any reasonable approximations.
b.If 0.0050 mol of NaOH is added to 100.mL of the solution in (a),calculate the pH of the resultant buffer.

Accepted Answer

a.2.22
b.3.27

Question 4

Increasing the concentrations of the components of a buffer solution will increase the buffer range.

Accepted Answer

A) True 
 B)False

Question 5

Which one of the following is the best representation of the titration curve which will be obtained in the titration of a weak acid (0.10 mol L-1)with a strong base of the same concentration?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) 
  
A) 
  
B) 
  
C) 
  
D) 
  
E)

Question 6

A phosphate buffer (H2PO4-/HPO42-)has a pH of 8.3.Which of the following changes will cause the pH to increase?

Accepted Answer

A) dissolving a small amount of Na2HPO4 
B) dissolving a small amount of NaH2PO4 
C) adding a small amount of dilute hydrochloric acid 
D) adding a small amount of dilute phosphoric acid 
E) making the buffer more concentrated by removing some water 
A) dissolving a small amount of Na2HPO4 
B) dissolving a small amount of NaH2PO4 
C) adding a small amount of dilute hydrochloric acid 
D) adding a small amount of dilute phosphoric acid 
E) making the buffer more concentrated by removing some water

Question 7

Write the ion product expression for silver sulfide,Ag2S.

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) 
  
A) 
  
B) 
  
C) 
  
D) 
  
E)

Question 8

Propanoic acid (CH3CH2COOH)has a Ka of 1.34 $\times$10-5.A 25.00 mL sample of 0.1000 mol L-1 propanoic acid (in flask)is titrated with 0.1000 mol L-1 NaOH solution,added from a buret.Carry out the calculations of the quantities indicated below.
a.The pH after 0.00 mL of NaOH are added.
b.The pH after 15.00 mL of NaOH are added.
c.The hydroxide ion concentration after 26.00 mL of NaOH are added.

Accepted Answer

a.2.94
b.5.05
c.1.96

Question 9

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO3)3.What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide?
Kf = 3.0 $\times$ 1033 for Al(OH)4-

Accepted Answer

A) 1.8 $\times$ 10-7 M 
B) 9.l $\times$ 10-18 M 
C) 1.0 $\times$ 10-31 M 
D) 3.3 $\times$ 10-34 M 
E) 7.l $\times$ 10-36 M 
A) 1.8 $\times$ 10-7 M 
B) 9.l $\times$ 10-18 M 
C) 1.0 $\times$ 10-31 M 
D) 3.3 $\times$ 10-34 M 
E) 7.l $\times$ 10-36 M

Question 10

The concentration of the complex ion in each of following solutions is 1.00 M.In which of the solutions will the concentration of the uncomplexed metal ion be the greatest?
Hg(CN)42- Kf = 9.3 $\times$ 1038
Be(OH)42- Kf = 4.0 $\times$ 1018
 Zn(OH)42- Kf = 3.0 $\times$ 1015
 Cu(NH3)42+ Kf = 5.6 $\times$ 1011
 CdI42- Kf = 1.0 $\times$ 106

Accepted Answer

A) Hg2+ 
B) Be2+ 
C) Zn2+ 
D) Cu2+ 
E) Cd2+ 
A) Hg2+ 
B) Be2+ 
C) Zn2+ 
D) Cu2+ 
E) Cd2+

Question 11

Which of the following indicators would be the best to use when 0.050 M benzoic acid (Ka = 6.6 $\times$ 10-5)is titrated with 0.05 M NaOH?

Accepted Answer

A) bromphenol blue,pH range: 3.0-4.5 
B) bromcresol green,pH range: 3.8-5.4 
C) alizarin,pH range: 5.7-7.2 
D) phenol red,pH range: 6.9-8.2 
E) phenolphthalein,pH range: 8.0-10.1 
A) bromphenol blue,pH range: 3.0-4.5 
B) bromcresol green,pH range: 3.8-5.4 
C) alizarin,pH range: 5.7-7.2 
D) phenol red,pH range: 6.9-8.2 
E) phenolphthalein,pH range: 8.0-10.1

Question 12

A 35.0-mL sample of 0.20 M LiOH is titrated with 0.25 M HCl.What is the pH of the solution after 23.0 mL of HCl have been added to the base?

Accepted Answer

A) 1.26 
B) 1.67 
C) 12.33 
D) 12.74 
E) 13.03 
A) 1.26 
B) 1.67 
C) 12.33 
D) 12.74 
E) 13.03

Question 13

What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH3COOH] = [CH3COO-] = 0.5 M?

Accepted Answer

A) The pH will increase slightly. 
B) The pH will increase significantly. 
C) The pH will decrease slightly. 
D) The pH will decrease significantly. 
E) Since it is a buffer solution,the pH will not be affected. 
A) The pH will increase slightly. 
B) The pH will increase significantly. 
C) The pH will decrease slightly. 
D) The pH will decrease significantly. 
E) Since it is a buffer solution,the pH will not be affected.

Question 14

Buffer solutions with the component concentrations shown below were prepared.Which of them should have the lowest pH?

Accepted Answer

A) [CH3COOH] = 0.25 M,[CH3COO-] = 0.25 M 
B) [CH3COOH] = 0.75 M,[CH3COO-] = 0.75 M 
C) [CH3COOH] = 0.75 M,[CH3COO-] = 0.25 M 
D) [CH3COOH] = 0.25 M,[CH3COO-] = 0.75 M 
E) [CH3COOH] = 1.00 M,[CH3COO-] = 1.00 M 
A) [CH3COOH] = 0.25 M,[CH3COO-] = 0.25 M 
B) [CH3COOH] = 0.75 M,[CH3COO-] = 0.75 M 
C) [CH3COOH] = 0.75 M,[CH3COO-] = 0.25 M 
D) [CH3COOH] = 0.25 M,[CH3COO-] = 0.75 M 
E) [CH3COOH] = 1.00 M,[CH3COO-] = 1.00 M

Question 15

The solubility of silver chloride _______________ when dilute nitric is added to it.

Accepted Answer

A) increases 
B) decreases 
C) does not change 
D) first increases,then decreases 
E) first decreases,then increases 
A) increases 
B) decreases 
C) does not change 
D) first increases,then decreases 
E) first decreases,then increases

Question 16

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH3COOH.What is the pH of this buffer? Ka = 1.8 $\times$ 10-5

Accepted Answer

A) 4.57 
B) 4.52 
C) 4.87 
D) 4.92 
E) 4.97 
A) 4.57 
B) 4.52 
C) 4.87 
D) 4.92 
E) 4.97

Question 17

What is the pH of a buffer that consists of 0.45 M CH3COOH and 0.35 M CH3COONa?
Ka = 1.8 $\times$10-5

Accepted Answer

A) 4.49 
B) 4.64 
C) 4.85 
D) 5.00 
E) 5.52 
A) 4.49 
B) 4.64 
C) 4.85 
D) 5.00 
E) 5.52

Question 18

Calculate the solubility of strontium fluoride,SrF2,in pure water.Ksp = 2.6 $\times$ 10-9

Accepted Answer

A) 1.4 $\times$ 10-3 M 
B) 3.4 $\times$ 10-4 M 
C) 8.7 $\times$ 10-4 M 
D) 5.l $\times$ 10-5 M 
E) -5 M 
A) 1.4 $\times$ 10-3 M 
B) 3.4 $\times$ 10-4 M 
C) 8.7 $\times$ 10-4 M 
D) 5.l $\times$ 10-5 M 
E) -5 M

Question 19

The solubility of salt MX (solubility product constant Ksp)in water will always be greater than that of salt MX3 (solubility product constant Ksp)provided that Ksp > K'sp.

Accepted Answer

A) True 
 B)False

Question 20

When a weak acid is titrated with a weak base,the pH at the equivalence point

Accepted Answer

A) is greater than 7.0. 
B) is equal to 7.0. 
C) is less than 7.0. 
D) is determined by the sizes of Ka and Kb. 
E) is no longer affected by addition of base. 
A) is greater than 7.0. 
B) is equal to 7.0. 
C) is less than 7.0. 
D) is determined by the sizes of Ka and Kb. 
E) is no longer affected by addition of base.

Exam 19: Ionic Equilibria in Aqueous Systems

Write the ion product expression for magnesium fluoride,MgF2.

A buffer is prepared by adding 100 mL of 0.50 M sodium hydroxide to 100 mL of 0.75 M propanoic acid.Is this a buffer solution,and if so,what is its pH?

Formic acid is a monoprotic acid with a Ka value of 1.8 ×\times× 10-4 at 25°C. a.Calculate the pH of a 0.200 mol L-1 solution of the acid,making any reasonable approximations. b.If 0.0050 mol of NaOH is added to 100.mL of the solution in (a),calculate the pH of the resultant buffer.

Increasing the concentrations of the components of a buffer solution will increase the buffer range.

Which one of the following is the best representation of the titration curve which will be obtained in the titration of a weak acid (0.10 mol L-1)with a strong base of the same concentration?

A phosphate buffer (H2PO4-/HPO42-)has a pH of 8.3.Which of the following changes will cause the pH to increase?

Write the ion product expression for silver sulfide,Ag2S.

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO3)3.What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? Kf = 3.0 ×\times× 1033 for Al(OH)4-

Which of the following indicators would be the best to use when 0.050 M benzoic acid (Ka = 6.6 ×\times× 10-5)is titrated with 0.05 M NaOH?

A 35.0-mL sample of 0.20 M LiOH is titrated with 0.25 M HCl.What is the pH of the solution after 23.0 mL of HCl have been added to the base?

What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH3COOH] = [CH3COO-] = 0.5 M?

Buffer solutions with the component concentrations shown below were prepared.Which of them should have the lowest pH?

The solubility of silver chloride _______________ when dilute nitric is added to it.

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH3COOH.What is the pH of this buffer? Ka = 1.8 ×\times× 10-5

What is the pH of a buffer that consists of 0.45 M CH3COOH and 0.35 M CH3COONa? Ka = 1.8 ×\times× 10-5

Calculate the solubility of strontium fluoride,SrF2,in pure water.Ksp = 2.6 ×\times× 10-9

The solubility of salt MX (solubility product constant Ksp)in water will always be greater than that of salt MX3 (solubility product constant Ksp)provided that Ksp > K'sp.

When a weak acid is titrated with a weak base,the pH at the equivalence point

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids,solids,and Phase Changes

The Properties of Solutions

The Main-Group Elements: Applying Principles of Bonding and Structure

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Thermodynamics: Entropy, free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Write the ion product expression for magnesium fluoride,MgF₂.

Formic acid is a monoprotic acid with a K_a value of 1.8 $\times$ 10^-4 at 25°C. a.Calculate the pH of a 0.200 mol L^-1 solution of the acid,making any reasonable approximations. b.If 0.0050 mol of NaOH is added to 100.mL of the solution in (a),calculate the pH of the resultant buffer.

Which one of the following is the best representation of the titration curve which will be obtained in the titration of a weak acid (0.10 mol L^-1)with a strong base of the same concentration?

A phosphate buffer (H₂PO₄^-/HPO₄^2-)has a pH of 8.3.Which of the following changes will cause the pH to increase?

Write the ion product expression for silver sulfide,Ag₂S.

The lab technician Anna Lytic adds 2.20 mol KOH to 1.00 L of 0.5 M Al(NO₃)₃.What is the concentration of aluminum ions after the aluminum nitrate has reacted with the potassium hydroxide? K_f = 3.0 $\times$ 10³³ for Al(OH)₄^-

Which of the following indicators would be the best to use when 0.050 M benzoic acid (K_a = 6.6 $\times$ 10^-5)is titrated with 0.05 M NaOH?

What will be the effect of adding 0.5 mL of 0.1 M NaOH to 100 mL of an acetate buffer in which [CH₃COOH] = [CH₃COO^-] = 0.5 M?

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH₃COOH.What is the pH of this buffer? K_a = 1.8 $\times$ 10^-5

What is the pH of a buffer that consists of 0.45 M CH₃COOH and 0.35 M CH₃COONa? K_a = 1.8 $\times$ 10^-5

Calculate the solubility of strontium fluoride,SrF₂,in pure water.K_sp = 2.6 $\times$ 10^-9

The solubility of salt MX (solubility product constant K_sp)in water will always be greater than that of salt MX₃ (solubility product constant K_sp)provided that K_sp > K'_sp.