Question 1

For the first-order reaction, A $\rarr$ products, if half of the initial concentration of A reacts in 20 min, then the remaining half will completely react in the next 20 min.

Accepted Answer

A) True 
 B)False

Question 2

Appropriate units for a second-order rate constant are

Accepted Answer

A) M/s. 
B) 1/M·s. 
C) 1/s. 
D) 1/M2·s. 
A) M/s. 
B) 1/M·s. 
C) 1/s. 
D) 1/M2·s.

Question 3

Nitrous oxide (N2O)decomposes at 600°C according to the balanced equation 2N2O(g)$\rarr$ 2N2(g)+ O2(g)
A reaction mechanism involving three steps is shown below. Identify all of the catalysts in the following mechanism.
Cl2(g)$\rarr$ 2Cl(g)
N2O(g)+ Cl(g)$\rarr$N2(g)+ ClO(g)(occurs twice)
ClO(g)+ ClO(g)$\rarr$Cl2(g)+ O2(g)

Accepted Answer

A) Cl 
B) Cl2 
C) ClO 
D) N2O 
E) ClO and Cl 
A) Cl 
B) Cl2 
C) ClO 
D) N2O 
E) ClO and Cl

Question 4

Use the following data to determine the rate law for the reaction shown below. 2NO + H2 $\rarr$N2O + H2O

Accepted Answer

A) rate = k[NO] 
B) rate = k[NO]2 
C) rate = k[NO][H2] 
D) rate = k[NO]2[H2] 
E) rate = k[NO]2[H2]2 
A) rate = k[NO] 
B) rate = k[NO]2 
C) rate = k[NO][H2] 
D) rate = k[NO]2[H2] 
E) rate = k[NO]2[H2]2

Question 5

The oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the net reaction H3AsO4 + 3I -  + 2 H3O + $\rarr$H3AsO3 + I3- + H2O. The experimental rate law for this reaction is rate = k [H3AsO4] [I-] [H3O+]. What is the order of the reaction with respect to I-?

Accepted Answer

The answer of The oxidation of iodide ions by arsenic...

Question 6

The activation energy for a certain reaction is 113 kJ/mol. By what factor (how many times)will the rate constant increase when the temperature is raised from 310 K to 325 K?

Accepted Answer

The answer of The activation energy for a certain reaction...

Question 7

The first-order decomposition of phosphene to phosphorus and hydrogen 4PH3(g)$\rarr$P4(g)+ 6H2(g)has a half-life of 35.0 s at 680°C. Starting with 520 mmHg of pure phosphene in an 8.00-L flask at 680°C, how long will it take for the total pressure in the flask to rise to 1.000 atm?

Accepted Answer

A) 628 s 
B) 33.4 s 
C) 51.2 s 
D) 111 s 
E) 48.3 s 
A) 628 s 
B) 33.4 s 
C) 51.2 s 
D) 111 s 
E) 48.3 s

Question 8

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518°C, the half-life for the second-order decomposition process, CH3CHO $\rarr$ CH4 + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour?

Accepted Answer

A) 327 mmHg 
B) 654 mmHg 
C) 37 mmHg 
D) 691 mmHg 
E) 728 mmHg 
A) 327 mmHg 
B) 654 mmHg 
C) 37 mmHg 
D) 691 mmHg 
E) 728 mmHg

Question 9

Nitric acid is formed by the gas-phase hydrolysis of N2O5. For the reaction N2O5 + H2O $\rarr$2HNO3, Ea(forward)= 15 kJ/mol and Ea(reverse)= 51 kJ/mol. Calculate $\Delta$Hrxn.

Accepted Answer

The answer of Nitric acid is formed by the gas-phase...

Question 10

The rate law for the reaction 2NO2 + O3 $\rarr$ N2O5 + O2 is rate = k[NO2][O3]. Which one of the following mechanisms is consistent with this rate law?

Accepted Answer

A) NO2 + NO2 $\rarr$ N2O4 (fast) N2O4 + O3 $\rarr$N2O5 + O2 (slow) 
B) NO2 + O3 $\rarr$ NO5 (fast) NO5 + NO5 $\rarr$N2O5 + 5/2O2 (slow) 
C) NO2 + O3 $\rarr$ NO3 + O2 (slow) NO3 + NO2 $\rarr$ N2O5 (fast) 
D) NO2 + NO2 $\rarr$ N2O2 + O2 (slow) N2O2 + O3 $\rarr$ N2O5 (fast) 
A) NO2 + NO2 $\rarr$ N2O4 (fast) N2O4 + O3 $\rarr$N2O5 + O2 (slow) 
B) NO2 + O3 $\rarr$ NO5 (fast) NO5 + NO5 $\rarr$N2O5 + 5/2O2 (slow) 
C) NO2 + O3 $\rarr$ NO3 + O2 (slow) NO3 + NO2 $\rarr$ N2O5 (fast) 
D) NO2 + NO2 $\rarr$ N2O2 + O2 (slow) N2O2 + O3 $\rarr$ N2O5 (fast)

Question 11

For the reaction whose rate law is rate = k[X], a plot of which of the following is a straight line?

Accepted Answer

A) [X] versus time 
B) ln [X] versus time 
C) 1/[X] versus time 
D) [X] versus 1/time 
E) ln [X] versus 1/time 
A) [X] versus time 
B) ln [X] versus time 
C) 1/[X] versus time 
D) [X] versus 1/time 
E) ln [X] versus 1/time

Question 12

A certain reaction A $\rarr$ products is second order in A. If this reaction is 85% complete in 12 minutes, how long would it take for the reaction to be 15% complete?

Accepted Answer

A) 110 s 
B) 27 s 
C) 62 s 
D) 130 s 
E) 22 s 
A) 110 s 
B) 27 s 
C) 62 s 
D) 130 s 
E) 22 s

Question 13

Calculate the activation energy, in kJ/mol, for the redox reaction Sn2+ + 2Co3+ $\rarr$ Sn4+ + 2Co2+.

Accepted Answer

A) 59.2 
B) 0.477 
C) 5.37 
D) 163 kJ 
E) 48.1 kJ 
A) 59.2 
B) 0.477 
C) 5.37 
D) 163 kJ 
E) 48.1 kJ

Question 14

The data below were determined for the reaction shown below. S2O82- + 3I - (aq) $\rarr$ 2SO42- + I3-   The rate law for this reaction must be:

Accepted Answer

A) rate = k[S2O82- ][I -]3 
B) rate = k[S2O82-] 
C) rate = k[S2O82-]2[I -]2 
D) rate = k[I -] 
E) rate = k[S2O82-][I -] 
A) rate = k[S2O82- ][I -]3 
B) rate = k[S2O82-] 
C) rate = k[S2O82-]2[I -]2 
D) rate = k[I -] 
E) rate = k[S2O82-][I -]

Question 15

Use the table of data shown below to calculate the average rate of the reaction A$\rarr$B between 10 s and 20 s.

Accepted Answer

5 * 10<sup

Question 16

At 25°C, by what factor is the reaction rate increased by a catalyst that reduces the activation energy of the reaction by 1.00 kJ/mol?

Accepted Answer

A) 1.63 
B) 123 
C) 1.04 
D) 1.50 
E) 2.53 
A) 1.63 
B) 123 
C) 1.04 
D) 1.50 
E) 2.53

Question 17

Hydrogen peroxide decomposes to water and oxygen gas, and the activation energy for this process is 42 kJ/mol. The hydrogen peroxide formed in biological processes is harmful to tissue, but the enzyme catalase catalyzes the decomposition hydrogen peroxide by lowering the activation energy to 7.0 kJ/mol. Assuming the frequency factor is the same for both processes and independent of temperature, calculate the temperature required for the uncatalyzed decomposition to proceed at the same rate as the enzyme-catalyzed decomposition at 37°C (normal human body temperature). Is this a reasonable temperature for a biological organism?

Accepted Answer

1600°C; no

Question 18

At a particular temperature the first-order gas-phase reaction N2O5 $\rarr$ 2NO2 + 1/2O2 has a half-life for the disappearance of dinitrogen pentoxide of 5130 s. Suppose 0.450 atm of N2O5 is introduced into an evacuated 2.00 L flask. What will be the total gas pressure inside the flask after 3.00 hours?

Accepted Answer

A) 0.969 atm 
B) 0.105 atm 
C) 0.795 atm 
D) 1.14 atm 
E) 0.864 atm 
A) 0.969 atm 
B) 0.105 atm 
C) 0.795 atm 
D) 1.14 atm 
E) 0.864 atm

Question 19

For the reaction X2 + Y + Z $\rarr$ XY + XZ, it is found that the rate equation is rate = k [X2][Y]. Why does the concentration of Z have no effect on the rate?

Accepted Answer

A) The concentration of Z is very small and the others are very large. 
B) Z must react in a step after the rate determining step. 
C) Z is an intermediate. 
D) The fraction of molecules of Z that have very high energies is zero. 
E) The activation energy for Z to react is very high. 
A) The concentration of Z is very small and the others are very large. 
B) Z must react in a step after the rate determining step. 
C) Z is an intermediate. 
D) The fraction of molecules of Z that have very high energies is zero. 
E) The activation energy for Z to react is very high.

Question 20

Solids cannot react with gases.

Accepted Answer

A) 1 and 2 
B) 1 and 3 
C) 1 and 4 
D) 2 and 3 
E) 3 and 4 
A) 1 and 2 
B) 1 and 3 
C) 1 and 4 
D) 2 and 3 
E) 3 and 4

For the first-order reaction, A $\rarr$ products, if half of the initial concentration of A reacts in 20 min, then the remaining half will completely react in the next 20 min.

Appropriate units for a second-order rate constant are

Use the following data to determine the rate law for the reaction shown below. 2NO + H₂ $\rarr$ N₂O + H₂O $Use the following data to determine the rate law for the reaction shown below. 2NO + H<sub>2</sub> \rarr N<sub>2</sub>O + H<sub>2</sub>O$

The activation energy for a certain reaction is 113 kJ/mol. By what factor (how many times)will the rate constant increase when the temperature is raised from 310 K to 325 K?

The first-order decomposition of phosphene to phosphorus and hydrogen 4PH₃(g) $\rarr$ P₄(g)+ 6H₂(g)has a half-life of 35.0 s at 680°C. Starting with 520 mmHg of pure phosphene in an 8.00-L flask at 680°C, how long will it take for the total pressure in the flask to rise to 1.000 atm?

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518°C, the half-life for the second-order decomposition process, CH₃CHO $\rarr$ CH₄ + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour?

Nitric acid is formed by the gas-phase hydrolysis of N₂O₅. For the reaction N₂O₅ + H₂O $\rarr$ 2HNO₃, E_a(forward)= 15 kJ/mol and E_a(reverse)= 51 kJ/mol. Calculate $\Delta$ H_rxn.

The rate law for the reaction 2NO₂ + O₃ $\rarr$ N₂O₅ + O₂ is rate = k[NO₂][O₃]. Which one of the following mechanisms is consistent with this rate law?

For the reaction whose rate law is rate = k[X], a plot of which of the following is a straight line?

A certain reaction A $\rarr$ products is second order in A. If this reaction is 85% complete in 12 minutes, how long would it take for the reaction to be 15% complete?

Calculate the activation energy, in kJ/mol, for the redox reaction Sn²⁺ + 2Co³⁺ $\rarr$ Sn⁴⁺ + 2Co²⁺. $Calculate the activation energy, in kJ/mol, for the redox reaction Sn<sup>2+</sup> + 2Co<sup>3</sup><sup>+</sup> \rarr Sn<sup>4+</sup> + 2Co<sup>2+</sup>.$

Use the table of data shown below to calculate the average rate of the reaction A $\rarr$ B between 10 s and 20 s. $Use the table of data shown below to calculate the average rate of the reaction A \rarr B between 10 s and 20 s.$

At 25°C, by what factor is the reaction rate increased by a catalyst that reduces the activation energy of the reaction by 1.00 kJ/mol?

For the reaction X₂ + Y + Z $\rarr$ XY + XZ, it is found that the rate equation is rate = k [X₂][Y]. Why does the concentration of Z have no effect on the rate?

Solids cannot react with gases.

Introduction

Atoms, Molecules, and Ions

Stoichiometry

Reactions in Aqueous Solution

Gases

Energy Relationships in Chemical Reactions

The Electronic Structure of Atoms

The Periodic Table

Chemical Bonding I: the Covalent Bond

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Introduction to Organic Chemistry

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Thermodynamics

Redox Reactions and Electrochemistry

The Chemistry of Coordination Compounds

Nuclear Chemistry

Organic Polymerssynthetic and Natural

Filters

Exam 14: Chemical Kinetics

For the first-order reaction, A →\rarr→ products, if half of the initial concentration of A reacts in 20 min, then the remaining half will completely react in the next 20 min.

Appropriate units for a second-order rate constant are

Use the following data to determine the rate law for the reaction shown below. 2NO + H2 →\rarr→ N2O + H2O

The oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the net reaction H3AsO4 + 3I - + 2 H3O + →\rarr→ H3AsO3 + I3- + H2O. The experimental rate law for this reaction is rate = k [H3AsO4] [I-] [H3O+]. What is the order of the reaction with respect to I-?

The activation energy for a certain reaction is 113 kJ/mol. By what factor (how many times)will the rate constant increase when the temperature is raised from 310 K to 325 K?

The first-order decomposition of phosphene to phosphorus and hydrogen 4PH3(g) →\rarr→ P4(g)+ 6H2(g)has a half-life of 35.0 s at 680°C. Starting with 520 mmHg of pure phosphene in an 8.00-L flask at 680°C, how long will it take for the total pressure in the flask to rise to 1.000 atm?

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518°C, the half-life for the second-order decomposition process, CH3CHO →\rarr→ CH4 + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour?

Nitric acid is formed by the gas-phase hydrolysis of N2O5. For the reaction N2O5 + H2O →\rarr→ 2HNO3, Ea(forward)= 15 kJ/mol and Ea(reverse)= 51 kJ/mol. Calculate Δ\DeltaΔ Hrxn.

The rate law for the reaction 2NO2 + O3 →\rarr→ N2O5 + O2 is rate = k[NO2][O3]. Which one of the following mechanisms is consistent with this rate law?

For the reaction whose rate law is rate = k[X], a plot of which of the following is a straight line?

A certain reaction A →\rarr→ products is second order in A. If this reaction is 85% complete in 12 minutes, how long would it take for the reaction to be 15% complete?

Calculate the activation energy, in kJ/mol, for the redox reaction Sn2+ + 2Co3+ →\rarr→ Sn4+ + 2Co2+.

The data below were determined for the reaction shown below. S2O82- + 3I - (aq) →\rarr→ 2SO42- + I3- The rate law for this reaction must be:

Use the table of data shown below to calculate the average rate of the reaction A →\rarr→ B between 10 s and 20 s.

At 25°C, by what factor is the reaction rate increased by a catalyst that reduces the activation energy of the reaction by 1.00 kJ/mol?

For the reaction X2 + Y + Z →\rarr→ XY + XZ, it is found that the rate equation is rate = k [X2][Y]. Why does the concentration of Z have no effect on the rate?

Solids cannot react with gases.

Introduction

Atoms, Molecules, and Ions

Stoichiometry

Reactions in Aqueous Solution

Gases

Energy Relationships in Chemical Reactions

The Electronic Structure of Atoms

The Periodic Table

Chemical Bonding I: the Covalent Bond

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Introduction to Organic Chemistry

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Thermodynamics

Redox Reactions and Electrochemistry

The Chemistry of Coordination Compounds

Nuclear Chemistry

Organic Polymerssynthetic and Natural

Filters

For the first-order reaction, A $\rarr$ products, if half of the initial concentration of A reacts in 20 min, then the remaining half will completely react in the next 20 min.

Use the following data to determine the rate law for the reaction shown below. 2NO + H₂ $\rarr$ N₂O + H₂O $Use the following data to determine the rate law for the reaction shown below. 2NO + H<sub>2</sub> \rarr N<sub>2</sub>O + H<sub>2</sub>O$

The first-order decomposition of phosphene to phosphorus and hydrogen 4PH₃(g) $\rarr$ P₄(g)+ 6H₂(g)has a half-life of 35.0 s at 680°C. Starting with 520 mmHg of pure phosphene in an 8.00-L flask at 680°C, how long will it take for the total pressure in the flask to rise to 1.000 atm?

When acetaldehyde at a pressure of 364 mmHg is introduced into an evacuated 500. mL flask at 518°C, the half-life for the second-order decomposition process, CH₃CHO $\rarr$ CH₄ + CO, is 410. s. What will the total pressure in the flask be after 1.00 hour?

Nitric acid is formed by the gas-phase hydrolysis of N₂O₅. For the reaction N₂O₅ + H₂O $\rarr$ 2HNO₃, E_a(forward)= 15 kJ/mol and E_a(reverse)= 51 kJ/mol. Calculate $\Delta$ H_rxn.

The rate law for the reaction 2NO₂ + O₃ $\rarr$ N₂O₅ + O₂ is rate = k[NO₂][O₃]. Which one of the following mechanisms is consistent with this rate law?

A certain reaction A $\rarr$ products is second order in A. If this reaction is 85% complete in 12 minutes, how long would it take for the reaction to be 15% complete?

Calculate the activation energy, in kJ/mol, for the redox reaction Sn²⁺ + 2Co³⁺ $\rarr$ Sn⁴⁺ + 2Co²⁺. $Calculate the activation energy, in kJ/mol, for the redox reaction Sn<sup>2+</sup> + 2Co<sup>3</sup><sup>+</sup> \rarr Sn<sup>4+</sup> + 2Co<sup>2+</sup>.$

Use the table of data shown below to calculate the average rate of the reaction A $\rarr$ B between 10 s and 20 s. $Use the table of data shown below to calculate the average rate of the reaction A \rarr B between 10 s and 20 s.$

For the reaction X₂ + Y + Z $\rarr$ XY + XZ, it is found that the rate equation is rate = k [X₂][Y]. Why does the concentration of Z have no effect on the rate?