Question 1

H2O2(l) $\rarr$ H2O(l)+ 1/2O2(g)

Accepted Answer

A) 1 < 3 < 2 
B) 2 < 3 < 1 
C) 2 < 1 < 3 
D) 3 < 2 < 1 
E) 3 < 1 < 2 
A) 1 < 3 < 2 
B) 2 < 3 < 1 
C) 2 < 1 < 3 
D) 3 < 2 < 1 
E) 3 < 1 < 2

Question 2

For the reaction H2(g)+ S(s) $\rarr$ H2S(g), $\Delta$H° = -20.2 kJ/mol and $\Delta$S° = +43.1 J/K·mol. Which of these statements is true?

Accepted Answer

A) The reaction is only spontaneous at low temperatures. 
B) The reaction is spontaneous at all temperatures. 
C) ($\Delta$G°) becomes less favorable as temperature increases. 
D) The reaction is spontaneous only at high temperatures. 
E) The reaction is at equilibrium at 25°C under standard conditions. 
A) The reaction is only spontaneous at low temperatures. 
B) The reaction is spontaneous at all temperatures. 
C) ($\Delta$G°) becomes less favorable as temperature increases. 
D) The reaction is spontaneous only at high temperatures. 
E) The reaction is at equilibrium at 25°C under standard conditions.

Question 3

Kw for the auto-ionization of water, H2O(l) $\rarr$ H+(aq)+ OH- (aq), is 1.0 * 10-14. What are the signs (+/-)of $\Delta$S° and $\Delta$H° for the reaction at 25°C?

Accepted Answer

A) ($\Delta$S°) = (+)and $\Delta$H° = (+) 
B) ($\Delta$S°) = (+)and $\Delta$H° = (-) 
C) ($\Delta$S°) = (-)and $\Delta$H° = (+) 
D) ($\Delta$S°) = (-)and $\Delta$H° = (-) 
A) ($\Delta$S°) = (+)and $\Delta$H° = (+) 
B) ($\Delta$S°) = (+)and $\Delta$H° = (-) 
C) ($\Delta$S°) = (-)and $\Delta$H° = (+) 
D) ($\Delta$S°) = (-)and $\Delta$H° = (-)

Question 4

Which one of the following reactions would you expect to have the lowest $\Delta$S°?

Accepted Answer

A) CH4(g)+ 2O2(g) $\rarr$CO2(g)+ 2H2O(g) 
B) C2H2(g)+ 5/2O2(g) $\rarr$ 2CO2(g)+ H2O(g) 
C) C2H4(g)+ O2(g) $\rarr$2CO2(g)+ 2H2O(g) 
D) C2H6(g)+ 7/2O2(g) $\rarr$ 2CO2(g)+ 3H2O(g) 
A) CH4(g)+ 2O2(g) $\rarr$CO2(g)+ 2H2O(g) 
B) C2H2(g)+ 5/2O2(g) $\rarr$ 2CO2(g)+ H2O(g) 
C) C2H4(g)+ O2(g) $\rarr$2CO2(g)+ 2H2O(g) 
D) C2H6(g)+ 7/2O2(g) $\rarr$ 2CO2(g)+ 3H2O(g)

Question 5

A negative sign for $\Delta$G indicates that, at constant T and P,

Accepted Answer

A) the reaction is exothermic. 
B) the reaction is endothermic. 
C) the reaction is fast. 
D) the reaction is spontaneous. 
E) ($\Delta$S) must be > 0. 
A) the reaction is exothermic. 
B) the reaction is endothermic. 
C) the reaction is fast. 
D) the reaction is spontaneous. 
E) ($\Delta$S) must be > 0.

Question 6

For the reaction CuS(s)+ H2(g) $\rarr$ H2S(g)+ Cu(s),
$\Delta$G°f (CuS)= -53.6 kJ/mol
$\Delta$G°f (H2S)= -33.6 kJ/mol
$\Delta$H°f (CuS)= -53.1 kJ/mol
$\Delta$H°f (H2S)= -20.6 kJ/mol
Calculate the value of the equilibrium constant (Kp)for this reaction at 298 K.

Accepted Answer

3.11 * 10<

Question 7

Using the thermodynamic data provided below, calculate Ksp for ZnS(s)at 25°.

Accepted Answer

2.4 * 10^-24

Question 8

Predict the sign of $\Delta$S for the process N2(g, 10 atm) $\rarr$ N2(g, 1atm).

Accepted Answer

The answer of Predict the sign of $\Delta$S for the...

Question 9

Sulfur can be separated from lead in the mineral galena, PbS(s), by "roasting" the ore in the presence of oxygen as shown in the following reaction:
2PbS(s)+ 3O2(g) $\rarr$2PbO(s)+ 2SO2(g)
Determine $\Delta$G for the above reaction at 850°C.

Accepted Answer

The answer of Sulfur can be separated from lead in...

Question 10

Given the following data, estimate the boiling point of carbon disulfide, CS2, assuming that $\Delta$S° and $\Delta$H° are temperature-independent.

Accepted Answer

The answer of Given the following data, estimate the boiling...

Question 11

In the gas phase, formic acid forms a dimmer, 2HCOOH(g) $\rarr$ (HCOOH)2(g). For this reaction, $\Delta$H° = -60.1 kJ/mol and $\Delta$G° = -13.9 kJ/mol at 25°C. Find the equilibrium constant (Kp)for this reaction at 75 °C.

Accepted Answer

A) 8960 
B) 273 
C) 0.120 
D) 8.33 
E) 1.12 * 10-4 
A) 8960 
B) 273 
C) 0.120 
D) 8.33 
E) 1.12 * 10-4

Question 12

Using the thermodynamic data provided below, calculate Ka1 for H2CO3(aq)at 25°.

Accepted Answer

5 * 10<sup>-7</sup>

Question 13

For the reaction SbCl5(g) $\rarr$ SbCl3(g)+ Cl2(g),
$\Delta$G°f (SbCl5)= -334.34 kJ/mol
$\Delta$G°f (SbCl3)= -301.25 kJ/mol
$\Delta$H°f (SbCl5)= -394.34 kJ/mol
$\Delta$H°f (SbCl3)= -313.80 kJ/mol
Calculate the value of the equilibrium constant (Kp)for this reaction at 298 K.

Accepted Answer

1.58 * 10<

Question 14

The heat of vaporization of water is 2.27 kJ/g. What is $\Delta$Svap per mole at the normal boiling point?

Accepted Answer

The answer of The heat of vaporization of water is...

Question 15

Ozone (O3)in the atmosphere can reaction with nitric oxide (NO): O3(g)+ NO(g)$\rarr$NO2(g)+ O2(g).
Calculate the $\Delta$G° for this reaction at 25°C. ($\Delta$H° = -199 kJ/mol, $\Delta$S° = -4.1 J/K·mol)

Accepted Answer

A) 1020 kJ/mol 
B) -1.22 * 103 kJ/mol 
C) 2.00 * 103 kJ/mol 
D) -1.42 * 103 kJ/mol 
E) -198 kJ/mol 
A) 1020 kJ/mol 
B) -1.22 * 103 kJ/mol 
C) 2.00 * 103 kJ/mol 
D) -1.42 * 103 kJ/mol 
E) -198 kJ/mol

Question 16

At 1500°C the equilibrium constant for the reaction CO(g)+ 2H2(g) $\rarr$ CH3OH(g)has the value Kp = 1.4 * 10-7. Calculate $\Delta$G° for this reaction at 1500°C.

Accepted Answer

A) 105 kJ/mol 
B) 1.07 kJ/mol 
C) -233 kJ/mol 
D) -105 kJ/mol 
E) 233 kJ/mol 
A) 105 kJ/mol 
B) 1.07 kJ/mol 
C) -233 kJ/mol 
D) -105 kJ/mol 
E) 233 kJ/mol

Question 17

MgCO3(s) $\rarr$MgO(s)+ CO2(g)

Accepted Answer

A) 1 < 2 < 3 
B) 2 < 3 < 1 
C) 3 < 2 < 1 
D) 2 < 1 < 3 
E) 1 < 3 < 2 
A) 1 < 2 < 3 
B) 2 < 3 < 1 
C) 3 < 2 < 1 
D) 2 < 1 < 3 
E) 1 < 3 < 2

Question 18

Determine the equilibrium constant Kp at 25°C for the reaction N2(g)+ 3H2(g) $\rarr$ 2NH3(g) [$\Delta$G°f (NH3(g))= -16.6 kJ/mol].

Accepted Answer

A) 1.52 * 10-6 
B) 6.60 * 105 
C) 8.28 * 10-2 
D) 2.60 
E) 13.4 
A) 1.52 * 10-6 
B) 6.60 * 105 
C) 8.28 * 10-2 
D) 2.60 
E) 13.4

Question 19

Consider the gas phase reaction shown below.
CH4(g)+ CF4(g) $\rarr$ CH3F(g)+ CHF3(g)
Will the standard entropy increase, decrease, or remain if the reaction proceeds from reactants to products, as written? Explain your reasoning.

Accepted Answer

The standard enthalpy will increase as t

Question 20

In the gas phase, methyl isocyanate (CH3NC)isomerizes to acetonitrile (CH3CN), H3C-N$\equiv$C (g) $\rarr$ H3C-C $\equiv$ N (g)
With $\Delta$H° = -89.5 kJ/mol and $\Delta$G° = -73.8 kJ/mol at 25°C. Find the equilibrium constant for this reaction at 100°C.

Accepted Answer

A) 1.68 * 10-10 
B) 5.96 * 109 
C) 2.16 * 1010 
D) 4.63 * 10-11 
E) 8.64 * 1012 
A) 1.68 * 10-10 
B) 5.96 * 109 
C) 2.16 * 1010 
D) 4.63 * 10-11 
E) 8.64 * 1012

H₂O₂(l) $\rarr$ H₂O(l)+ ¹/₂O₂(g)

For the reaction H₂(g)+ S(s) $\rarr$ H₂S(g), $\Delta$ H° = -20.2 kJ/mol and $\Delta$ S° = +43.1 J/K·mol. Which of these statements is true?

K_w for the auto-ionization of water, H₂O(l) $\rarr$ H⁺(aq)+ OH^- (aq), is 1.0 * 10^-14. What are the signs (+/-)of $\Delta$ S° and $\Delta$ H° for the reaction at 25°C?

Which one of the following reactions would you expect to have the lowest $\Delta$ S°?

A negative sign for $\Delta$ G indicates that, at constant T and P,

For the reaction CuS(s)+ H₂(g) $\rarr$ H₂S(g)+ Cu(s), $\Delta$ G°_f (CuS)= -53.6 kJ/mol $\Delta$ G°_f (H₂S)= -33.6 kJ/mol $\Delta$ H°_f (CuS)= -53.1 kJ/mol $\Delta$ H°_f (H₂S)= -20.6 kJ/mol Calculate the value of the equilibrium constant (K_p)for this reaction at 298 K.

Using the thermodynamic data provided below, calculate K_sp for ZnS(s)at 25°.

Predict the sign of $\Delta$ S for the process N₂(g, 10 atm) $\rarr$ N₂(g, 1atm).

In the gas phase, formic acid forms a dimmer, 2HCOOH(g) $\rarr$ (HCOOH)₂(g). For this reaction, $\Delta$ H° = -60.1 kJ/mol and $\Delta$ G° = -13.9 kJ/mol at 25°C. Find the equilibrium constant (K_p)for this reaction at 75 °C.

Using the thermodynamic data provided below, calculate K_a1 for H₂CO₃(aq)at 25°.

The heat of vaporization of water is 2.27 kJ/g. What is $\Delta$ S_vap per mole at the normal boiling point?

Ozone (O₃)in the atmosphere can reaction with nitric oxide (NO): O₃(g)+ NO(g) $\rarr$ NO₂(g)+ O₂(g). Calculate the $\Delta$ G° for this reaction at 25°C. ( $\Delta$ H° = -199 kJ/mol, $\Delta$ S° = -4.1 J/K·mol)

At 1500°C the equilibrium constant for the reaction CO(g)+ 2H₂(g) $\rarr$ CH₃OH(g)has the value K_p = 1.4 * 10^-7. Calculate $\Delta$ G° for this reaction at 1500°C.

MgCO₃(s) $\rarr$ MgO(s)+ CO₂(g)

Determine the equilibrium constant K_p at 25°C for the reaction N₂(g)+ 3H₂(g) $\rarr$ 2NH₃(g) [ $\Delta$ G°_f (NH₃(g))= -16.6 kJ/mol].

Consider the gas phase reaction shown below. CH₄(g)+ CF₄(g) $\rarr$ CH₃F(g)+ CHF₃(g) Will the standard entropy increase, decrease, or remain if the reaction proceeds from reactants to products, as written? Explain your reasoning.

In the gas phase, methyl isocyanate (CH₃NC)isomerizes to acetonitrile (CH₃CN), H₃C-N $\equiv$ C (g) $\rarr$ H₃C-C $\equiv$ N (g) With $\Delta$ H° = -89.5 kJ/mol and $\Delta$ G° = -73.8 kJ/mol at 25°C. Find the equilibrium constant for this reaction at 100°C.

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 Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Redox Reactions and Electrochemistry

The Chemistry of Coordination Compounds

Nuclear Chemistry

Organic Polymerssynthetic and Natural

Filters

Exam 18: Thermodynamics

H2O2(l) →\rarr→ H2O(l)+ 1/2O2(g)

For the reaction H2(g)+ S(s) →\rarr→ H2S(g), Δ\DeltaΔ H° = -20.2 kJ/mol and Δ\DeltaΔ S° = +43.1 J/K·mol. Which of these statements is true?

Kw for the auto-ionization of water, H2O(l) →\rarr→ H+(aq)+ OH- (aq), is 1.0 * 10-14. What are the signs (+/-)of Δ\DeltaΔ S° and Δ\DeltaΔ H° for the reaction at 25°C?

Which one of the following reactions would you expect to have the lowest Δ\DeltaΔ S°?

A negative sign for Δ\DeltaΔ G indicates that, at constant T and P,

For the reaction CuS(s)+ H2(g) →\rarr→ H2S(g)+ Cu(s), Δ\DeltaΔ G°f (CuS)= -53.6 kJ/mol Δ\DeltaΔ G°f (H2S)= -33.6 kJ/mol Δ\DeltaΔ H°f (CuS)= -53.1 kJ/mol Δ\DeltaΔ H°f (H2S)= -20.6 kJ/mol Calculate the value of the equilibrium constant (Kp)for this reaction at 298 K.