Question 1

Which one of the following statements is NOT true concerning the equation below?
N2(g) + 3 H2(g) → 2 NH3(g) ΔH°rxn = -459.0 kJ

Accepted Answer

A)   The production of 1.00 mole of ammonia is accompanied by the production of 229.5 kJ of heat.
B)   The complete reaction of 1.00 moles of nitrogen requires 459 kJ of heat.
C)   The complete reaction of 1.00 moles of hydrogen produces 153 kJ of heat.
D)   The complete reaction of 0.8278 moles of hydrogen requires 0.2759 moles of nitrogen.
E)   The reaction is exothermic.

Question 2

Two aqueous solutions are both at room temperature and are then mixed in a coffee cup calorimeter.The reaction causes the temperature of the resulting solution to fall below room temperature.Which of the following statements is TRUE?

Accepted Answer

A)   The products have a lower potential energy than the reactants.
B)   This type of experiment will provide data to calculate ΔErxn.
C)   The reaction is exothermic.
D)   Energy is leaving the system during reaction.
E)   None of the above statements are true.

Question 3

Define thermal energy.

Accepted Answer

A)   energy associated with the temperature of an object
B)   energy associated with the motion of an object
C)   energy associated with the force of an object
D)   energy associated with the gravity of an object
E)   energy associated with the position or composition of an object

Question 4

When 0.455 g of anthracene,C14H10,is combusted in a bomb calorimeter that has a water jacket containing 500.0 g of water,the temperature of the water increases by 8.63°C.Assuming that the specific heat of water is 4.18 J/(g ∙ °C) ,and that the heat absorption by the calorimeter is negligible,estimate the enthalpy of combustion per mole of anthracene.

Accepted Answer

A)   +39.7 kJ/mol
B)   -39.7 kJ/mol
C)   -7060 kJ/mol
D)   -8120 kJ/mol

Question 5

When 1.50 g of Ba(s) is added to 100.00 g of water in a container open to the atmosphere,the reaction shown below occurs and the temperature of the resulting solution rises from 22.00°C to 33.10°C.If the specific heat of the solution is 4.18 J/(g ∙ °C) ,calculate 2O(l) → Ba(OH) 2(aq) + H2(g)    = ? A)  -431 kJ B)  -3.14 kJ C)  +3.14 kJ D)  +431 kJ" class="answers-bank-image d-inline" rel="preload" > for the reaction,as written. Ba(s) + 2 H2O(l) → Ba(OH) 2(aq) + H2(g)  2O(l) → Ba(OH) 2(aq) + H2(g)    = ? A)  -431 kJ B)  -3.14 kJ C)  +3.14 kJ D)  +431 kJ" class="answers-bank-image d-inline" rel="preload" > = ?

Accepted Answer

A)   -431 kJ
B)   -3.14 kJ
C)   +3.14 kJ
D)   +431 kJ

Question 6

Use the information provided to determine ΔH°rxn for the following reaction ΔH°f (kJ/mol) 3 Fe2O3(s) + CO(g) → 2 Fe3O4(s) + CO2(g) ΔH°rxn = ?
Fe2O3(s) -824
Fe3O4(s) -1118
CO(g) -111
CO2(g) -394

Accepted Answer

A)   +277 kJ
B)   -577 kJ
C)   -47 kJ
D)   +144 kJ
E)   -111 kJ

Question 7

Define heat capacity.

Accepted Answer

A)   the quantity of heat required to lower the temperature of 1 mole of a substance by 1°C
B)   the quantity of heat required to change a system's temperature by 1°C
C)   the quantity of heat required to lower the temperature of 1 gram of a substance by 1°C
D)   the quantity of heat required to raise the temperature of 1 g of a substance by 1°F
E)   the quantity of heat required to lower the temperature of 1 liter of a substance by 1°C

Question 8

Calculate the amount of heat (in kJ) necessary to raise the temperature of 53.8 g benzene by 50.6 K.The specific heat capacity of benzene is 1.05 J/g°C.

Accepted Answer

A)   1.61 kJ
B)   16.6 kJ
C)   2.59 kJ
D)   2.86 kJ
E)   3.85 kJ

Question 9

Which of the following processes are endothermic?

Accepted Answer

A)   K⁺(g)  + I⁻(g)  → KI(s) 
B)   2 Br(g)  → Br2(g) 
C)   Ca(s)  → Ca(g) 
D)   2 Na(s)  + 2(g)  
C)   Ca(s)  → Ca(g)  
D)   2 Na(s)  +   O2(g)  → Na2O(s)  
E)   None of the above are endothermic." class="answers-bank-image d-inline" rel="preload" > O2(g)  → Na2O(s) 
E)   None of the above are endothermic.

Question 10

A balloon is inflated from 0.0100 L to 0.400 L against an external pressure of 10.00 atm.How much work is done in joules? 101.3 J = 1 L × atm

Accepted Answer

A)   -39.5 J
B)   39.5 J
C)   0. 395 J
D)   -0. 395 J
E)   -395 J

Question 11

A 50.0-g sample of liquid water at 25.0°C is mixed with 29.0 g of water at 45.0°C.The final temperature of the water is ________°C.

Accepted Answer

A)   102
B)   27.6
C)   35.0
D)   142
E)   32.3

Question 12

Define potential energy.

Accepted Answer

A)   energy associated with the temperature of an object
B)   energy associated with the motion of an object
C)   energy associated with the force of an object
D)   energy associated with the gravity of an object
E)   energy associated with the position or composition of an object

Question 13

Using the following equation for the combustion of octane,calculate the heat of reaction for 400.0 g of octane.The molar mass of octane is 114.33 g/mole. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O ΔH°rxn = -11018 kJ

Accepted Answer

A)   19280 kJ
B)   19.28 kJ
C)   38560 kJ
D)   50400 kJ

Question 14

Which of the following processes are exothermic?

Accepted Answer

A)   the second ionization energy of Mg
B)   the sublimation of Li
C)   the breaking the bond of I2
D)   the formation of NaBr from its constituent elements in their standard state
E)   None of the above are exothermic.

Question 15

Which of the following processes are exothermic?

Accepted Answer

A)   Cl2(g)  → 2Cl(g) 
B)   Br(g)  + e⁻ → Br⁻(g) 
C)   Li(s)  → Li(g) 
D)   NaF(s)  → Na⁺(g)  + F⁻(g) 
E)   None of the above are exothermic.

Question 16

The specific heat capacity of liquid mercury is 0.14 J/gK.How many joules of heat are needed to raise the temperature of 5.00 g of mercury from 15.0°C to 36.5°C?

Accepted Answer

A)   7.7 × 102 J
B)   15 J
C)   36 J
D)   0.0013 J
E)   1.7 J

Question 17

Give the temperature and pressure for the standard state for a liquid.

Accepted Answer

1 atmosphe...

Question 18

How much energy is required to decompose 765 g of PCl3,according to the reaction below? The molar mass of PCl3 is 137.32 g/mol and may be useful.
4 PCl3(g) → P4(s) + 6 Cl2(g) ΔH°rxn = +1207 kJ

Accepted Answer

A)   2.31 × 103 kJ
B)   4.33 × 103 kJ
C)   6.72 × 103 kJ
D)   1.68 × 103 kJ
E)   5.95 × 103 kJ

Question 19

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) ΔH = ?

Accepted Answer

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

Question 20

A piece of iron (C=0.449 J/g°C) and a piece of gold (C=0.128 J/g°C) have identical masses.If the iron has an initial temperature of 488 K and the gold has an initial temperature of 308 K,which of the following statements is TRUE of the outcome when the two metals are placed in contact with one another? Assume no heat is lost to the surroundings.

Accepted Answer

A)   Since the two metals have the same mass, the final temperature of the two metals will be 398 K, exactly halfway between the two initial temperatures.
B)   Since the two metals have the same mass, but the specific heat capacity of gold is much smaller than that of iron, the final temperature of the two metals will be closer to 308 K than to 488 K.
C)   Energy will flow from the gold to the iron until the two metals are at the same temperature.
D)   Since the two metals have the same mass, the thermal energy contained in each metal after equilibrium will be the same.
E)   None of the above are true.

Exam 10: Thermochemistry

Which one of the following statements is NOT true concerning the equation below? N₂(g) + 3 H₂(g) → 2 NH₃(g) ΔH°_rxn= -459.0 kJ

Correct Answer
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The specific heat capacity of liquid mercury is 0.14 J/gK.How many joules of heat are needed to raise the temperature of 5.00 g of mercury from 15.0°C to 36.5°C?

Correct Answer
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Use the information provided to determine ΔH°_rxn for the following reaction ΔH°_f (kJ/mol) 3 Fe₂O₃(s) + CO(g) → 2 Fe₃O₄(s) + CO₂(g) ΔH°_rxn= ? Fe₂O₃(s) -824 Fe₃O₄(s) -1118 CO(g) -111 CO₂(g) -394

Correct Answer
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Calculate the amount of heat (in kJ) necessary to raise the temperature of 53.8 g benzene by 50.6 K.The specific heat capacity of benzene is 1.05 J/g°C.

Correct Answer
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Correct Answer
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Define heat capacity.

Correct Answer
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Two aqueous solutions are both at room temperature and are then mixed in a coffee cup calorimeter.The reaction causes the temperature of the resulting solution to fall below room temperature.Which of the following statements is TRUE?

Correct Answer
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Which of the following processes are exothermic?

Correct Answer
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Using the following equation for the combustion of octane,calculate the heat of reaction for 400.0 g of octane.The molar mass of octane is 114.33 g/mole. 2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O ΔH°_rxn= -11018 kJ

Correct Answer
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Correct Answer
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A balloon is inflated from 0.0100 L to 0.400 L against an external pressure of 10.00 atm.How much work is done in joules? 101.3 J = 1 L × atm

Correct Answer
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How much energy is required to decompose 765 g of PCl₃,according to the reaction below? The molar mass of PCl₃ is 137.32 g/mol and may be useful. 4 PCl₃(g) → P₄(s) + 6 Cl₂(g) ΔH°_rxn = +1207 kJ

Correct Answer
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Give the temperature and pressure for the standard state for a liquid.

Correct Answer
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1 atmosphe...
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Define thermal energy.

Correct Answer
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Correct Answer
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Which of the following processes are endothermic?

Correct Answer
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Define potential energy.

Correct Answer
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A 50.0-g sample of liquid water at 25.0°C is mixed with 29.0 g of water at 45.0°C.The final temperature of the water is ________°C.

Correct Answer
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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) ΔH = ?

Correct Answer
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Which of the following processes are exothermic?

Correct Answer
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Exam 10: Thermochemistry

Which one of the following statements is NOT true concerning the equation below? N2(g) + 3 H2(g) → 2 NH3(g) ΔH°rxn = -459.0 kJ

Correct AnswerverifiedShow Answer

The specific heat capacity of liquid mercury is 0.14 J/gK.How many joules of heat are needed to raise the temperature of 5.00 g of mercury from 15.0°C to 36.5°C?

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Use the information provided to determine ΔH°rxn for the following reaction ΔH°f (kJ/mol) 3 Fe2O3(s) + CO(g) → 2 Fe3O4(s) + CO2(g) ΔH°rxn = ? Fe2O3(s) -824 Fe3O4(s) -1118 CO(g) -111 CO2(g) -394

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Calculate the amount of heat (in kJ) necessary to raise the temperature of 53.8 g benzene by 50.6 K.The specific heat capacity of benzene is 1.05 J/g°C.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Define heat capacity.

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Two aqueous solutions are both at room temperature and are then mixed in a coffee cup calorimeter.The reaction causes the temperature of the resulting solution to fall below room temperature.Which of the following statements is TRUE?

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Which of the following processes are exothermic?

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Using the following equation for the combustion of octane,calculate the heat of reaction for 400.0 g of octane.The molar mass of octane is 114.33 g/mole. 2 C8H18 + 25 O2 → 16 CO2 + 18 H2O ΔH°rxn = -11018 kJ

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A balloon is inflated from 0.0100 L to 0.400 L against an external pressure of 10.00 atm.How much work is done in joules? 101.3 J = 1 L × atm

Correct AnswerverifiedShow Answer

How much energy is required to decompose 765 g of PCl3,according to the reaction below? The molar mass of PCl3 is 137.32 g/mol and may be useful. 4 PCl3(g) → P4(s) + 6 Cl2(g) ΔH°rxn = +1207 kJ

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Give the temperature and pressure for the standard state for a liquid.

Correct Answerverified1 atmosphe...View AnswerShow Answer

Define thermal energy.

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Correct AnswerverifiedShow Answer

Which of the following processes are endothermic?

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Define potential energy.

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A 50.0-g sample of liquid water at 25.0°C is mixed with 29.0 g of water at 45.0°C.The final temperature of the water is ________°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) ΔH = ?

Correct AnswerverifiedShow Answer

Which of the following processes are exothermic?

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Which one of the following statements is NOT true concerning the equation below? N₂(g) + 3 H₂(g) → 2 NH₃(g) ΔH°_rxn= -459.0 kJ

Correct Answer
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Correct Answer
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Use the information provided to determine ΔH°_rxn for the following reaction ΔH°_f (kJ/mol) 3 Fe₂O₃(s) + CO(g) → 2 Fe₃O₄(s) + CO₂(g) ΔH°_rxn= ? Fe₂O₃(s) -824 Fe₃O₄(s) -1118 CO(g) -111 CO₂(g) -394

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Using the following equation for the combustion of octane,calculate the heat of reaction for 400.0 g of octane.The molar mass of octane is 114.33 g/mole. 2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O ΔH°_rxn= -11018 kJ

Correct Answer
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Correct Answer
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Correct Answer
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How much energy is required to decompose 765 g of PCl₃,according to the reaction below? The molar mass of PCl₃ is 137.32 g/mol and may be useful. 4 PCl₃(g) → P₄(s) + 6 Cl₂(g) ΔH°_rxn = +1207 kJ

Correct Answer
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Correct Answer
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1 atmosphe...
View Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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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) ΔH = ?

Correct Answer
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Correct Answer
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