Question 1

What is the work in joules done on the system to compress He gas from 24.0 L to 12.5 L against a pressure of 1.5 atm at a constant temperature of 37.4 °C?

Accepted Answer

A)  5.5 × 103 J
B)  -17 J
C)  17 J
D)  1.7 × 103 J
E)  -1.7 × 103 J

Question 2

When 1.50 mol of CH4(g) reacts with excess Cl2(g) at constant pressure according to the chemical equation shown below,1062 kJ of heat are released.Calculate the value of ΔH for this reaction,as written.
2 CH4(g) + 3 Cl2(g) → 2 CHCl3(l) + 3 H2(g)

4(g) reacts with excess Cl2(g) at constant pressure according to the chemical equation shown below,1062 kJ of heat are released.Calculate the value of ΔH for this reaction,as written. 2 CH4(g) + 3 Cl2(g) → 2 CHCl3(l) + 3 H2(g)      H° = ? A) -1420 kJ mol-1 B) -708 kJ mol-1 C) +708 kJ mol-1 D) +1420 kJ mol-1" class="answers-bank-image d-inline" rel="preload" > H° = ?

Accepted Answer

A)  -1420 kJ mol-1
B)  -708 kJ mol-1
C)  +708 kJ mol-1
D)  +1420 kJ mol-1

Question 3

Given that ΔfH° [Ag2S(s) ] = -32.6 kJ/mole,what is the enthalpy change for the precipitation of argentite,Ag2S(s) ?
ΔfH° [Ag+(aq) ] = +105.6 kJ/mol
ΔfH° [S2-(aq) ] = +33.05 kJ/mol

Accepted Answer

A)  -276.9 kJ/mol
B)  -106.1 kJ/mol
C)  +171.2 kJ/mol
D)  +106.1 kJ/mol
E)  +138.7 kJ/mol

Question 4

The complete combustion of propane,C3H8(g) ,is represented by the equation:
C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(l) ΔrH° = -2220 kJ/mol
How much heat is evolved in the complete combustion of 2.50 g C3H8(g) ?

Accepted Answer

A)  245 kJ
B)  50.4 kJ
C)  126 kJ
D)  5.56 kJ
E)  2.22 kJ

Question 5

100.0 g of Cu (specific heat = 0.385 J/g °C) at 100.0 °C is added to 140.0 mL of H2O (specific heat = 4.184 J/g °C) at 25.0 °C.What is the final temperature of the mixture?

Accepted Answer

A)  56.3 °C
B)  29.6 °C
C)  62.5 °C
D)  91.4 °C
E)  33.7 °C

Question 6

The maximum amount of work is provided by a reversible process because equilibrium between the system and the surroundings is always maintained.

Accepted Answer

A) True 
 B)False

Question 7

Some "beetles" defend themselves by spraying hot quinone,C6H4O2(l) ,at their enemies.Calculate △rH° for this reaction.
C6H4(OH) 2(l) + H2O2(l) → C6H4O2(l) + 2 H2O(l) 
Given: C6H4(OH) 2(l) → C6H4O2(l) + H2(g) +177.4 kJ/mol
The standard enthalpies of formation of H2O2(l) and H2O(l) are -187.4 and -285.8 kJ/mol,respectively.

Accepted Answer

A)  -206.8 kJ/mol
B)  -384.2 kJ/mol
C)  -561.6 kJ/mol
D)  +79.00 kJ/mol

Question 8

In the presence of excess oxygen,methane gas burns in a constant-pressure system to yield carbon dioxide and water: 
CH4(g) +2O2 (g) → CO2(g) + 2H2O (l)  
4(g) +2O2 (g) → CO2(g) + 2H2O (l)     H = -890.0 kJ Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure. A) -105.7 kJ B) 0.0342 kJ C) -0.0095 kJ D) 29.3 kJ E) -1.06 × 105 kJ" class="answers-bank-image d-inline" rel="preload" > H = -890.0 kJ
Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure.

Accepted Answer

A)  -105.7 kJ
B)  0.0342 kJ
C)  -0.0095 kJ
D)  29.3 kJ
E)  -1.06 × 105 kJ

Question 9

A system that absorbs heat is an exothermic system.

Accepted Answer

A) True 
 B)False

Question 10

The specific heat capacity of liquid water is 4.184 J g-1k-1.How many joules of heat are needed to raise the temperature of 6.00 g of water from 36.0 °C to 75.0 °C?

Accepted Answer

A)  56.0 J
B)  978 J
C)  2.78 × -1k-1.How many joules of heat are needed to raise the temperature of 6.00 g of water from 36.0 °C to 75.0 °C? 
A)  56.0 J 
B)  978 J 
C)  2.78 ×   J 
D)  1.79 ×   J 
E)  52.3 J" class="answers-bank-image d-inline" rel="preload" > J
D)  1.79 × -1k-1.How many joules of heat are needed to raise the temperature of 6.00 g of water from 36.0 °C to 75.0 °C? 
A)  56.0 J 
B)  978 J 
C)  2.78 ×   J 
D)  1.79 ×   J 
E)  52.3 J" class="answers-bank-image d-inline" rel="preload" > J
E)  52.3 J

Question 11

For the reaction H2(g) + 1/2 O2(g) → H2O(g) ΔrH° = -241.8 kJ/mol,
What quantity of heat is liberated by the reaction of 10.0 L of O2 measured at 22.0 °C and 742 mmHg?

Accepted Answer

A)  120 kJ
B)  2610 kJ
C)  1310 kJ
D)  195 kJ
E)  97.5 kJ

Question 12

A certain reaction releases 10.1 kJ at constant volume and at constant pressure releases 8.4 kJ.What is △U for the reaction?

Accepted Answer

A)  -10.1 kJ
B)  -8.4 kJ
C)  +8.4 kJ
D)  -1.7 kJ

Question 13

Oxygen gas at 34.5 °C is compressed from 45.7 L to 34.5 L against a constant pressure of 750 mmHg.What is the work done in joules by the system?

Accepted Answer

A)  1.12 × 103 J
B)  -1.12 × 103 J
C)  9.09 × 104 J
D)  -9.09 × 104 J
E)  4.55 × 103 J

Question 14

The specific heat capacity of methane gas is 2.20 J g-1k-1.How many joules of heat are needed to raise the temperature of 5.00 g of methane from 36.0 °C to 75.0 °C?

Accepted Answer

A)  88.6 J
B)  429 J
C)  1221 J
D)  0.0113 J
E)  22.9 J

Question 15

A 5.00 g sample of liquid water at 25.0 °C is heated by the addition of 145 J of energy.The final temperature of the water is ________ °C.The specific heat capacity of liquid water is

Accepted Answer

A)  146
B)  25.1
C)  -18.1
D)  31.9
E)  6.94

Question 16

Cyclohexanol,C6H12O,has a heat of combustion of -890.7 kcal/mol.A sample containing 0.708 g of cyclohexanol undergoes complete combustion in a bomb calorimeter that has a heat capacity of 2.70 kcal/ °C.What is the final temperature if the initial water temperature is 27.0 °C?

Accepted Answer

A)  24.7 °C
B)  29.3 °C
C)  27.4 °C
D)  26.6 °C
E)  31.4 °C

Question 17

Determine △rH° for the decomposition of hydrogen peroxide.
H2O2(l) →1/2 O2(g) + H2O(l) 
Given: H2(g) + O2(g) → H2O2(l) △rH° = -187.78 kJ/mol
H2(g) + 1/2 O2(g) → H2O(l) △rH° = -285.83 kJ/mol

Accepted Answer

A)  -98.05 kJ/mol
B)  +93.89 kJ/mol
C)  -191.94 kJ/mol
D)  -93.89 kJ/mol

Question 18

Given that ΔfH°[CO(g) ] = -110.5 kJ/mol and ΔfH° [COCl2(g) ] = -219.1 kJ/mol,what is the enthalpy of reaction for the formation of phosgene,COCl2 from carbon monoxide,CO,and chlorine gas,Cl2(g) ?

Accepted Answer

A)  +110.5 kJ /mol
B)  -110.5 kJ/mol
C)  +329.6 kJ /mol
D)  -108.6 kJ/mol
E)  -219.1 kJ/mol

Question 19

For a process at constant pressure,49,600 calories of heat are released.This quantity of heat is equivalent to:

Accepted Answer

A)  4.82 × 10-6 J
B)  1.19 × 104 J
C)  1.24 × 104 J
D)  2.08 × 105 J

Question 20

Choose the INCORRECT statement.

Accepted Answer

A)  The surroundings are the part of the universe that is studied.
B)  Thermal energy is energy associated with random molecular motion.
C)  Chemical energy is associated with chemical bonds and intermolecular forces.
D)  Energy is the capacity to do work.
E)  Work is done when a force acts through a distance.

Exam 7: Thermochemistry

Given that Δ_fH° [Ag₂S(s) ] = -32.6 kJ/mole,what is the enthalpy change for the precipitation of argentite,Ag₂S(s) ? Δ_fH° [Ag⁺(aq) ] = +105.6 kJ/mol Δ_fH° [S^2-(aq) ] = +33.05 kJ/mol

Correct Answer
verified

The complete combustion of propane,C₃H₈(g) ,is represented by the equation: C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(l) Δ_rH° = -2220 kJ/mol How much heat is evolved in the complete combustion of 2.50 g C₃H₈(g) ?

Correct Answer
verified

For a process at constant pressure,49,600 calories of heat are released.This quantity of heat is equivalent to:

Correct Answer
verified

A certain reaction releases 10.1 kJ at constant volume and at constant pressure releases 8.4 kJ.What is △U for the reaction?

Correct Answer
verified

100.0 g of Cu (specific heat = 0.385 J/g °C) at 100.0 °C is added to 140.0 mL of H₂O (specific heat = 4.184 J/g °C) at 25.0 °C.What is the final temperature of the mixture?

Correct Answer
verified

Determine △_rH° for the decomposition of hydrogen peroxide. H₂O₂(l) →1/2 O₂(g) + H₂O(l) Given: H₂(g) + O₂(g) → H₂O₂(l) △_rH° = -187.78 kJ/mol H₂(g) + 1/2 O₂(g) → H₂O(l) △_rH° = -285.83 kJ/mol

Correct Answer
verified

A system that absorbs heat is an exothermic system.

Correct Answer
verified

A 5.00 g sample of liquid water at 25.0 °C is heated by the addition of 145 J of energy.The final temperature of the water is ________ °C.The specific heat capacity of liquid water is

Correct Answer
verified

Cyclohexanol,C₆H₁₂O,has a heat of combustion of -890.7 kcal/mol.A sample containing 0.708 g of cyclohexanol undergoes complete combustion in a bomb calorimeter that has a heat capacity of 2.70 kcal/ °C.What is the final temperature if the initial water temperature is 27.0 °C?

Correct Answer
verified

The maximum amount of work is provided by a reversible process because equilibrium between the system and the surroundings is always maintained.

Correct Answer
verified

What is the work in joules done on the system to compress He gas from 24.0 L to 12.5 L against a pressure of 1.5 atm at a constant temperature of 37.4 °C?

Correct Answer
verified

Given that Δ_fH°[CO(g) ] = -110.5 kJ/mol and Δ_fH° [COCl₂(g) ] = -219.1 kJ/mol,what is the enthalpy of reaction for the formation of phosgene,COCl₂ from carbon monoxide,CO,and chlorine gas,Cl₂(g) ?

Correct Answer
verified

The specific heat capacity of methane gas is 2.20 J g^-1k^-1.How many joules of heat are needed to raise the temperature of 5.00 g of methane from 36.0 °C to 75.0 °C?

Correct Answer
verified

Choose the INCORRECT statement.

Correct Answer
verified

For the reaction H₂(g) + 1/2 O₂(g) → H₂O(g) Δ_rH° = -241.8 kJ/mol, What quantity of heat is liberated by the reaction of 10.0 L of O₂ measured at 22.0 °C and 742 mmHg?

Correct Answer
verified

Oxygen gas at 34.5 °C is compressed from 45.7 L to 34.5 L against a constant pressure of 750 mmHg.What is the work done in joules by the system?

Correct Answer
verified

Correct Answer
verified

In the presence of excess oxygen,methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH₄(g) +2O₂ (g) → CO₂(g) + 2H₂O (l) H = -890.0 kJ Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure.

Correct Answer
verified

The specific heat capacity of liquid water is 4.184 J g^-1k^-1.How many joules of heat are needed to raise the temperature of 6.00 g of water from 36.0 °C to 75.0 °C?

Correct Answer
verified

When 1.50 mol of CH₄(g) reacts with excess Cl₂(g) at constant pressure according to the chemical equation shown below,1062 kJ of heat are released.Calculate the value of ΔH for this reaction,as written. 2 CH₄(g) + 3 Cl₂(g) → 2 CHCl₃(l) + 3 H₂(g) H° = ?

Correct Answer
verified

Exam 7: Thermochemistry

Given that ΔfH° [Ag2S(s) ] = -32.6 kJ/mole,what is the enthalpy change for the precipitation of argentite,Ag2S(s) ? ΔfH° [Ag+(aq) ] = +105.6 kJ/mol ΔfH° [S2-(aq) ] = +33.05 kJ/mol

Correct AnswerverifiedShow Answer

The complete combustion of propane,C3H8(g) ,is represented by the equation: C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(l) ΔrH° = -2220 kJ/mol How much heat is evolved in the complete combustion of 2.50 g C3H8(g) ?

Correct AnswerverifiedShow Answer

For a process at constant pressure,49,600 calories of heat are released.This quantity of heat is equivalent to:

Correct AnswerverifiedShow Answer

A certain reaction releases 10.1 kJ at constant volume and at constant pressure releases 8.4 kJ.What is △U for the reaction?

Correct AnswerverifiedShow Answer

100.0 g of Cu (specific heat = 0.385 J/g °C) at 100.0 °C is added to 140.0 mL of H2O (specific heat = 4.184 J/g °C) at 25.0 °C.What is the final temperature of the mixture?

Correct AnswerverifiedShow Answer

Determine △rH° for the decomposition of hydrogen peroxide. H2O2(l) →1/2 O2(g) + H2O(l) Given: H2(g) + O2(g) → H2O2(l) △rH° = -187.78 kJ/mol H2(g) + 1/2 O2(g) → H2O(l) △rH° = -285.83 kJ/mol

Correct AnswerverifiedShow Answer

A system that absorbs heat is an exothermic system.

Correct AnswerverifiedShow Answer

A 5.00 g sample of liquid water at 25.0 °C is heated by the addition of 145 J of energy.The final temperature of the water is ________ °C.The specific heat capacity of liquid water is

Correct AnswerverifiedShow Answer

Cyclohexanol,C6H12O,has a heat of combustion of -890.7 kcal/mol.A sample containing 0.708 g of cyclohexanol undergoes complete combustion in a bomb calorimeter that has a heat capacity of 2.70 kcal/ °C.What is the final temperature if the initial water temperature is 27.0 °C?

Correct AnswerverifiedShow Answer

The maximum amount of work is provided by a reversible process because equilibrium between the system and the surroundings is always maintained.

Correct AnswerverifiedShow Answer

What is the work in joules done on the system to compress He gas from 24.0 L to 12.5 L against a pressure of 1.5 atm at a constant temperature of 37.4 °C?

Correct AnswerverifiedShow Answer

Given that ΔfH°[CO(g) ] = -110.5 kJ/mol and ΔfH° [COCl2(g) ] = -219.1 kJ/mol,what is the enthalpy of reaction for the formation of phosgene,COCl2 from carbon monoxide,CO,and chlorine gas,Cl2(g) ?

Correct AnswerverifiedShow Answer

The specific heat capacity of methane gas is 2.20 J g-1k-1.How many joules of heat are needed to raise the temperature of 5.00 g of methane from 36.0 °C to 75.0 °C?

Correct AnswerverifiedShow Answer

Choose the INCORRECT statement.

Correct AnswerverifiedShow Answer

For the reaction H2(g) + 1/2 O2(g) → H2O(g) ΔrH° = -241.8 kJ/mol, What quantity of heat is liberated by the reaction of 10.0 L of O2 measured at 22.0 °C and 742 mmHg?

Correct AnswerverifiedShow Answer

Oxygen gas at 34.5 °C is compressed from 45.7 L to 34.5 L against a constant pressure of 750 mmHg.What is the work done in joules by the system?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

In the presence of excess oxygen,methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH4(g) +2O2 (g) → CO2(g) + 2H2O (l) H = -890.0 kJ Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure.

Correct AnswerverifiedShow Answer

The specific heat capacity of liquid water is 4.184 J g-1k-1.How many joules of heat are needed to raise the temperature of 6.00 g of water from 36.0 °C to 75.0 °C?

Correct AnswerverifiedShow Answer

When 1.50 mol of CH4(g) reacts with excess Cl2(g) at constant pressure according to the chemical equation shown below,1062 kJ of heat are released.Calculate the value of ΔH for this reaction,as written. 2 CH4(g) + 3 Cl2(g) → 2 CHCl3(l) + 3 H2(g) H° = ?

Correct AnswerverifiedShow Answer

Given that Δ_fH° [Ag₂S(s) ] = -32.6 kJ/mole,what is the enthalpy change for the precipitation of argentite,Ag₂S(s) ? Δ_fH° [Ag⁺(aq) ] = +105.6 kJ/mol Δ_fH° [S^2-(aq) ] = +33.05 kJ/mol

Correct Answer
verified

The complete combustion of propane,C₃H₈(g) ,is represented by the equation: C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(l) Δ_rH° = -2220 kJ/mol How much heat is evolved in the complete combustion of 2.50 g C₃H₈(g) ?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

100.0 g of Cu (specific heat = 0.385 J/g °C) at 100.0 °C is added to 140.0 mL of H₂O (specific heat = 4.184 J/g °C) at 25.0 °C.What is the final temperature of the mixture?

Correct Answer
verified

Determine △_rH° for the decomposition of hydrogen peroxide. H₂O₂(l) →1/2 O₂(g) + H₂O(l) Given: H₂(g) + O₂(g) → H₂O₂(l) △_rH° = -187.78 kJ/mol H₂(g) + 1/2 O₂(g) → H₂O(l) △_rH° = -285.83 kJ/mol

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Cyclohexanol,C₆H₁₂O,has a heat of combustion of -890.7 kcal/mol.A sample containing 0.708 g of cyclohexanol undergoes complete combustion in a bomb calorimeter that has a heat capacity of 2.70 kcal/ °C.What is the final temperature if the initial water temperature is 27.0 °C?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Given that Δ_fH°[CO(g) ] = -110.5 kJ/mol and Δ_fH° [COCl₂(g) ] = -219.1 kJ/mol,what is the enthalpy of reaction for the formation of phosgene,COCl₂ from carbon monoxide,CO,and chlorine gas,Cl₂(g) ?

Correct Answer
verified

The specific heat capacity of methane gas is 2.20 J g^-1k^-1.How many joules of heat are needed to raise the temperature of 5.00 g of methane from 36.0 °C to 75.0 °C?

Correct Answer
verified

Correct Answer
verified

For the reaction H₂(g) + 1/2 O₂(g) → H₂O(g) Δ_rH° = -241.8 kJ/mol, What quantity of heat is liberated by the reaction of 10.0 L of O₂ measured at 22.0 °C and 742 mmHg?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

In the presence of excess oxygen,methane gas burns in a constant-pressure system to yield carbon dioxide and water: CH₄(g) +2O₂ (g) → CO₂(g) + 2H₂O (l) H = -890.0 kJ Calculate the value of q (kJ) in this exothermic reaction when 1.90 g of methane is combusted at constant pressure.

Correct Answer
verified

The specific heat capacity of liquid water is 4.184 J g^-1k^-1.How many joules of heat are needed to raise the temperature of 6.00 g of water from 36.0 °C to 75.0 °C?

Correct Answer
verified

When 1.50 mol of CH₄(g) reacts with excess Cl₂(g) at constant pressure according to the chemical equation shown below,1062 kJ of heat are released.Calculate the value of ΔH for this reaction,as written. 2 CH₄(g) + 3 Cl₂(g) → 2 CHCl₃(l) + 3 H₂(g) H° = ?

Correct Answer
verified