Question 1

How many millilitres of 0.0850 mol L-1 NaOH(aq)are required to titrate 25.0 mL of   (aq)to the equivalence point?

Accepted Answer

A) 21.2 
B) 0.245 
C) 3.92 
D) 0.153 
E) 29.5 
A) 21.2 
B) 0.245 
C) 3.92 
D) 0.153 
E) 29.5

Question 2

The titration curve for 10.0 mL of 0.100 M H3PO4(aq)with 0.100 M NaOH(aq)is given below.  
Estimate the pKa2 of H3PO4.

Accepted Answer

A) 7.2 
B) 4.8 
C) 9.8 
D) 2.2 
E) 6.5 
A) 7.2 
B) 4.8 
C) 9.8 
D) 2.2 
E) 6.5

Question 3

Phenolphthalein may be used as an indicator for the titration of:

Accepted Answer

A) a weak base with a strong acid 
B) a weak acid with a weak base 
C) any acid and base 
D) a weak acid with a strong base 
E) phenolphthalein cannot be used as an indicator 
A) a weak base with a strong acid 
B) a weak acid with a weak base 
C) any acid and base 
D) a weak acid with a strong base 
E) phenolphthalein cannot be used as an indicator

Question 4

Calculate the pH of a 1.00 L solution of 0.100 M NH3(aq)after the addition of 0.010 mol HCl(g).For NH3,pKb = 4.74.

Accepted Answer

A) 10.21 
B) 9.26 
C) 8.31 
D) 11.46 
E) 7.00 
A) 10.21 
B) 9.26 
C) 8.31 
D) 11.46 
E) 7.00

Question 5

The common ion in an aqueous solution mixture of a weak base and a strong base is the hydronium ion.

Accepted Answer

A) True 
 B)False

Question 6

What is the pH of a solution made by dissolving 2.16 g of sodium benzoate (NaC6H5CO2)in a sufficient volume of 0.033 M aqueous benzoic acid solution to prepare 500.0 mL of buffer? [Ka for benzoic acid is 6.3 × 10-5]

Accepted Answer

A) 4.16 
B) 4.37 
C) 4.64 
D) 5.77 
E) 6.30 
A) 4.16 
B) 4.37 
C) 4.64 
D) 5.77 
E) 6.30

Question 7

25 ml of 0.10 M aqueous acetic acid is titrated with 0.10 M NaOH(aq).What is the pH before any NaOH(aq)is added? Ka for acetic acid = 1.8 × 10-5.

Accepted Answer

A) 1.0 
B) 5.7 
C) 2.9 
D) 4.3 
E) 2.2 
A) 1.0 
B) 5.7 
C) 2.9 
D) 4.3 
E) 2.2

Question 8

The pH of a buffer depends mainly on the pKa of the weak acid component of the buffer.

Accepted Answer

A) True 
 B)False

Question 9

Determine the pH of the following aqueous solution.Initial concentrations are given.
[HC2H3O2] = 0.250 M,[HCl] = 0.120 M Ka (acetic acid)= 1.8 × 10-5

Accepted Answer

A) 0.60 
B) 0.92 
C) 0.43 
D) 4.74 
E) 13.08 
A) 0.60 
B) 0.92 
C) 0.43 
D) 4.74 
E) 13.08

Question 10

In 0.100 M HC2H3O2(aq),[H3O+(aq)] = [C2H3O2-(aq)] = 1.3 × 10-3 M.If a few drops of concentrated HCl(aq)are added to this solution,the C2H3O2-(aq)concentration is:

Accepted Answer

A) -3 M 
B) > 1.3 × 10-3 M 
C) = 1.3 × 10-3 M 
D) 0.100 M 
A) -3 M 
B) > 1.3 × 10-3 M 
C) = 1.3 × 10-3 M 
D) 0.100 M

Question 11

What is the pH of an aqueous buffer solution that is 0.211 mol L-1 in lactic acid and 0.111 mol L-1 in sodium lactate? The   Of lactic acid is 1.4 ×  .

Accepted Answer

A) 14.28 
B) 10.43 
C) 5.48 
D) 3.57 
E) 4.13 
A) 14.28 
B) 10.43 
C) 5.48 
D) 3.57 
E) 4.13

Question 12

Twenty-five milliliters of 0.10 M HCl(aq)is titrated with 0.10 M NaOH(aq).What is the pH at equivalence?

Accepted Answer

A) 7.0 
B) 6.2 
C) 7.5 
D) 8.6 
E) 7.1 
A) 7.0 
B) 6.2 
C) 7.5 
D) 8.6 
E) 7.1

Question 13

Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0.State what color the indicator will assume in the following solution: 0.20 M KOH(aq).

Accepted Answer

A) red 
B) yellow 
C) red-yellow mixture 
D) orange 
E) The indicator keeps its original color. 
A) red 
B) yellow 
C) red-yellow mixture 
D) orange 
E) The indicator keeps its original color.

Question 14

In a solution prepared by mixing equal volumes of 0.20 M aqueous acetic acid and 0.20 M aqueous hydrobromic acid,the common ion is ________.

Accepted Answer

A) Br-  
B) C2H3O22-  
C) H2C2H3O2  
D) H2Br+  
E) H3O+  
A) Br-  
B) C2H3O22-  
C) H2C2H3O2  
D) H2Br+  
E) H3O+

Question 15

It is easier to calculate the pH of an aqueous solution of sodium carbonate than for sodium hydrogen carbonate because there is only one hydrolysis reaction instead of two.

Accepted Answer

A) True 
 B)False

Question 16

In the titration of a solution of HCN(aq)with NaOH(aq),the equivalence point occurs at a pH greater than 7.

Accepted Answer

A) True 
 B)False

Question 17

Calculate the pH of an aqueous solution that is 0.295 mol L-1 in sodium formate (HCOONa)and   In formic acid (HCOOH).The   Of formic acid is 1.77 ×   .

Accepted Answer

A) 3.910 
B) 3.587 
C) 13.84 
D) 10.10 
E) 4.963 
A) 3.910 
B) 3.587 
C) 13.84 
D) 10.10 
E) 4.963

Question 18

An aqueous solution is prepared by dissolving 0.23 mol of hydrazoic acid and 0.27 mol of sodium azide in water sufficient to yield 1.00 L of solution.The addition of 0.05 mol of NaOH to this buffer solution causes the pH to increase slightly.The pH does not increase drastically because the NaOH reacts with the ________ present in the buffer solution.The  
Of hydrazoic acid is 1.9 × 10-5.

Accepted Answer

A)    O 
B)    
C) azide 
D) hydrazoic acid 
E) This is a buffer solution: the pH does not change upon addition of acid or base. 
A)    O 
B)    
C) azide 
D) hydrazoic acid 
E) This is a buffer solution: the pH does not change upon addition of acid or base.

Question 19

A 25.0 mL sample of 0.150 mol L-1 aqueous hydrazoic acid is titrated with a 0.150 mol L-1 NaOH(aq)solution.What is the pH after 13.3 mL of base is added? 
The   Of hydrazoic acid is 1.9 × 10-5.

Accepted Answer

A) 4.45 
B) 1.34 
C) 3.03 
D) 4.78 
E) 4.66 
A) 4.45 
B) 1.34 
C) 3.03 
D) 4.78 
E) 4.66

Question 20

Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0.State what color the indicator will assume in the following solution: 0.10 M NH4NO3(aq).

Accepted Answer

A) red 
B) yellow 
C) red-yellow mixture 
D) The indicator is its original color. 
E) There is not enough information to answer this question. 
A) red 
B) yellow 
C) red-yellow mixture 
D) The indicator is its original color. 
E) There is not enough information to answer this question.

Exam 17: Additional Aspects of Acidbase Equilibria

How many millilitres of 0.0850 mol L-1 NaOH(aq)are required to titrate 25.0 mL of (aq)to the equivalence point?

The titration curve for 10.0 mL of 0.100 M H3PO4(aq)with 0.100 M NaOH(aq)is given below. Estimate the pKa2 of H3PO4.

Phenolphthalein may be used as an indicator for the titration of:

Calculate the pH of a 1.00 L solution of 0.100 M NH3(aq)after the addition of 0.010 mol HCl(g).For NH3,pKb = 4.74.

The common ion in an aqueous solution mixture of a weak base and a strong base is the hydronium ion.

What is the pH of a solution made by dissolving 2.16 g of sodium benzoate (NaC6H5CO2)in a sufficient volume of 0.033 M aqueous benzoic acid solution to prepare 500.0 mL of buffer? [Ka for benzoic acid is 6.3 × 10-5]

25 ml of 0.10 M aqueous acetic acid is titrated with 0.10 M NaOH(aq).What is the pH before any NaOH(aq)is added? Ka for acetic acid = 1.8 × 10-5.

The pH of a buffer depends mainly on the pKa of the weak acid component of the buffer.

Determine the pH of the following aqueous solution.Initial concentrations are given. [HC2H3O2] = 0.250 M,[HCl] = 0.120 M Ka (acetic acid)= 1.8 × 10-5

In 0.100 M HC2H3O2(aq),[H3O+(aq)] = [C2H3O2-(aq)] = 1.3 × 10-3 M.If a few drops of concentrated HCl(aq)are added to this solution,the C2H3O2-(aq)concentration is:

What is the pH of an aqueous buffer solution that is 0.211 mol L-1 in lactic acid and 0.111 mol L-1 in sodium lactate? The Of lactic acid is 1.4 × .

Twenty-five milliliters of 0.10 M HCl(aq)is titrated with 0.10 M NaOH(aq).What is the pH at equivalence?

Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0.State what color the indicator will assume in the following solution: 0.20 M KOH(aq).

In a solution prepared by mixing equal volumes of 0.20 M aqueous acetic acid and 0.20 M aqueous hydrobromic acid,the common ion is ________.

It is easier to calculate the pH of an aqueous solution of sodium carbonate than for sodium hydrogen carbonate because there is only one hydrolysis reaction instead of two.

In the titration of a solution of HCN(aq)with NaOH(aq),the equivalence point occurs at a pH greater than 7.

Calculate the pH of an aqueous solution that is 0.295 mol L-1 in sodium formate (HCOONa)and In formic acid (HCOOH).The Of formic acid is 1.77 × .

A 25.0 mL sample of 0.150 mol L-1 aqueous hydrazoic acid is titrated with a 0.150 mol L-1 NaOH(aq)solution.What is the pH after 13.3 mL of base is added? The Of hydrazoic acid is 1.9 × 10-5.

Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0.State what color the indicator will assume in the following solution: 0.10 M NH4NO3(aq).

Matter: Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Valence Bond and Molecular Orbital Theories

Intermolecular Forces: Liquids and Solids

Spontaneous Change: Entropy and Gibbs Energy

Solutions and Their Physical Properties

Principles of Chemical Equilibrium

Acids and Bases

Solubility and Complex-Ion Equilibria

Electrochemistry

Chemical Kinetics

Chemistry of the Main-Group Elements I: Groups 1,2,13,and 14

Chemistry of the Main-Group Elements Ii: Groups 18,17,16,15,and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry

Structures of Organic Compounds

Reactions of Organic Compounds

Chemistry of the Living State

Filters

How many millilitres of 0.0850 mol L^-1 NaOH(aq)are required to titrate 25.0 mL of (aq)to the equivalence point?

The titration curve for 10.0 mL of 0.100 M H₃PO₄(aq)with 0.100 M NaOH(aq)is given below. Estimate the pK_a2 of H₃PO₄.

Calculate the pH of a 1.00 L solution of 0.100 M NH₃(aq)after the addition of 0.010 mol HCl(g).For NH₃,pK_b = 4.74.

What is the pH of a solution made by dissolving 2.16 g of sodium benzoate (NaC₆H₅CO₂)in a sufficient volume of 0.033 M aqueous benzoic acid solution to prepare 500.0 mL of buffer? [K_a for benzoic acid is 6.3 × 10^-5]

25 ml of 0.10 M aqueous acetic acid is titrated with 0.10 M NaOH(aq).What is the pH before any NaOH(aq)is added? K_a for acetic acid = 1.8 × 10^-5.

The pH of a buffer depends mainly on the pK_a of the weak acid component of the buffer.

Determine the pH of the following aqueous solution.Initial concentrations are given. [HC₂H₃O₂] = 0.250 M,[HCl] = 0.120 M K_a(acetic acid)= 1.8 × 10^-5

In 0.100 M HC₂H₃O₂(aq),[H₃O⁺(aq)] = [C₂H₃O₂^-(aq)] = 1.3 × 10^-3 M.If a few drops of concentrated HCl(aq)are added to this solution,the C₂H₃O₂^-(aq)concentration is:

What is the pH of an aqueous buffer solution that is 0.211 mol L^-1 in lactic acid and 0.111 mol L^-1 in sodium lactate? The Of lactic acid is 1.4 × .

Calculate the pH of an aqueous solution that is 0.295 mol L^-1 in sodium formate (HCOONa)and In formic acid (HCOOH).The Of formic acid is 1.77 × .

A 25.0 mL sample of 0.150 mol L^-1 aqueous hydrazoic acid is titrated with a 0.150 mol L^-1 NaOH(aq)solution.What is the pH after 13.3 mL of base is added? The Of hydrazoic acid is 1.9 × 10^-5.

Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0.State what color the indicator will assume in the following solution: 0.10 M NH₄NO₃(aq).