Question 1

Two solutions,initially at 24.69 °C,are mixed in a coffee cup calorimeter (Ccal = 105.5 J °C-1) .When a 200.0 mL volume of 0.100 mol L-1 AgNO3 solution is mixed with a 100.0 mL sample of 0.100 mol L-1 NaCl solution,the temperature in the calorimeter rises to 25.16 °C.Determine the  DrD _ { \mathrm { r } }Dr​  H°,in units of kJ  mol−1\mathrm { mol } ^ { - 1 }mol−1  .Assume that the density and heat capacity of the solutions is the same as that of water. Hint: Write a balanced reaction for the process.

Accepted Answer

A)  -32 kJ mol-1
B)  -78 kJ mol-1
C)  -64 kJ mol-1
D)  -25 kJ mol-1
E)  -52 kJ mol-1

Question 2

A piece of iron (mass = 25.0 g) at 398 K is placed in a styrofoam coffee cup containing 25.0 mL of water at 298 K.Assuming that no heat is lost to the cup or the surroundings,what will the final temperature of the water be? The specific heat capacity of iron = 0.449 J  g−1g ^ { - 1 }g−1  °C-1 and water = 4.184 J  g−1g ^ { - 1 }g−1  °C-1.

Accepted Answer

A)  348 K
B)  308 K
C)  287 K
D)  325 K
E)  388 K

Question 3

Calculate the internal energy change,ΔrU,for the combustion of 29.3 g of vitamin C (C6H8O6,molar mass = 176.124 g mol-1) if the combustion inside a bomb calorimeter,Ccal = 8.31 kJ °C-1,causes a temperature change from 21.5 °C to 68.3 °C.

Accepted Answer

A)  -1.78 × 103 kJ mol-1
B)  -2.34 × 103 kJ mol-1
C)  -6.03 × 103 kJ mol-1
D)  -9.19 × 102 kJ mol-1
E)  -1.67 × 102 kJ mol-1

Question 4

The specific heat capacity of liquid mercury is 0.14 J  g−1g ^ { - 1 }g−1   K−1\mathrm { K } ^ { - 1 }K−1  .How many joules of heat are needed to raise the temperature of 4.00 g of mercury from 19.0°C to 39.5°C?

Accepted Answer

A)  5.9 × 102 J
B)  33 J
C)  0.72 J
D)  0.0017 J
E)  11 J

Question 5

Which of the following statements is TRUE?

Accepted Answer

A)  State functions do not depend on the path taken to arrive at a particular state.
B)   DrU can be determined using constant volume calorimetry.
C)  Energy is neither created nor destroyed,excluding nuclear reactions.
D)   DrH can be determined using constant pressure calorimetry.
E)  All of the above are true.

Question 6

A 6.55 g sample of aniline (C6H5NH2,molar mass = 93.13 g  mol−1\mathrm { mol } ^ { - 1 }mol−1  ) was combusted in a bomb calorimeter.If the temperature rose by 32.9 °C,use the information below to determine the heat capacity of the calorimeter. 4C6H5NH2(l) + 35O2(g) ? 24CO2(g) + 14H2O(g) + 4NO2(g) 
DrU= -3.20 × 103 kJ mol-1

Accepted Answer

A)  97.3 kJ  ∘C−1{ } ^ { \circ } \mathrm { C } ^ { - 1 }∘C−1 
B)  38.9 kJ  ∘C−1{ } ^ { \circ } \mathrm { C } ^ { - 1 }∘C−1 
C)  5.94 kJ  ∘C−1{ } ^ { \circ } \mathrm { C } ^ { - 1 }∘C−1 
D)  6.84 kJ  ∘C−1{ } ^ { \circ } \mathrm { C } ^ { - 1 }∘C−1 
E)  12.8 kJ  ∘C−1{ } ^ { \circ } \mathrm { C } ^ { - 1 }∘C−1

Question 7

Calculate the final temperature of 82.1 g of molecular hydrogen (specific heat capacity = 14.304 J g-1 °C-1) initially at 5.48 °C that absorbs 57 kJ of energy from the surroundings.

Accepted Answer

A)  14 °C
B)  24 °C
C)  34 °C
D)  44 °C
E)  54 °C

Question 8

Using the following equation for the combustion of octane,calculate the amount of moles of oxygen that reacts with 100.0 g of octane.The molar mass of octane is 114.33 g  mol−1\mathrm { mol } ^ { - 1 }mol−1  .The molar mass of carbon dioxide is 44.0095 g  mol−1\mathrm { mol } ^ { - 1 }mol−1  . 2C8H18 + 25O2 ? 16CO2 + 18H2O 
DrH° = -11018 kJ

Accepted Answer

A)  18.18 moles
B)  6.997 moles
C)  14.00 moles
D)  8.000 moles
E)  10.93 moles

Question 9

The specific heat capacity of methane gas is 2.20 J  g−1g ^ { - 1 }g−1   K−1\mathrm { K } ^ { - 1 }K−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)  17.2 J
B)  0.0113 J
C)  88.6 J
D)  1.22 × 103 J
E)  429 J

Question 10

A piece of iron (C = 0.449 J g-1 °C-1 and a piece of gold (C = 0.128 J g-1 °C-1) have identical masses.If the iron has an initial temperature of 498 K and the gold has an initial temperature of 298 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 298 K than to 498 K.
C)  Since the two metals have the same mass,the thermal energy contained in the iron and gold after reaching thermal equilibrium will be the same.
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 is true.

Question 11

The specific heat of copper is 0.385 J  g−1g ^ { - 1 }g−1   K−1\mathrm { K } ^ { - 1 }K−1  .If 34.2 g of copper,initially at 21.0 °C,absorbs 4.689 kJ,what will be the final temperature of the copper?

Accepted Answer

A)  21.4 °C
B)  23.8 °C
C)  356 °C
D)  377 °C

Question 12

A balloon is inflated from 0.0100 L to 0.500 L against an external pressure of 10.00 bar.How much work is done in joules? (100 J = 1 L bar)

Accepted Answer

A)  -49.0J
B)  49.0 J
C)  0.490 J
D)  -0.490 J
E)  -490 J

Question 13

Explain the difference between ΔH and ΔU.

Accepted Answer

Change in enthalpy (ΔH)only tracks the e...

Question 14

An unknown metal alloy,specific heat capacity = 0.372 J g-1 °C-1,has a temperature change of +21.7 °C after a heat transfer of 216.4 J.Calculate the mass of the alloy in question.

Accepted Answer

A)  14.8 g
B)  19.0 g
C)  36.2 g
D)  21.5 g
E)  26.8 g

Question 15

A 100.0 mL sample of 0.300 mol L-1 NaOH is mixed with a 100.0 mL sample of 0.300 mol L-1 HNO3 in a coffee cup calorimeter.If both solutions were initially at 35.00 °C and the temperature of the resulting solution was recorded as 37.00 °C,determine the  DrD _ { \mathrm { r } }Dr​  H° (in units of kJ  mol−1\mathrm { mol } ^ { - 1 }mol−1  ) for the neutralization reaction between aqueous NaOH and HNO3 .Assume 1) that no heat is lost to the calorimeter or the surroundings,and 2) that the density and the heat capacity of the resulting solution are the same as water.

Accepted Answer

A)  -55.7 kJ mol-1
B)  -169 kJ mol-1
C)  -16.7 kJ mol-1
D)  -27.9 kJ mol-1
E)  -34.4 kJ mol-1

Question 16

The combustion of titanium with oxygen produces titanium dioxide: 
Ti(s) +  O2\mathrm { O } _ { 2 }O2​  (g) ?  TiO2\mathrm { TiO } _ { 2 }TiO2​  (s) 
When 2.090 g of titanium is combusted in a bomb calorimeter,the temperature of the calorimeter increases from 25.00 °C to 91.30 °C.In a separate experiment,the heat capacity of the calorimeter is measured to be 9.84 kJ  K−1\mathrm { K } ^ { - 1 }K−1  .The heat of reaction for the combustion of a mole of Ti in this calorimeter is ________ kJ  mol−1\mathrm { mol } ^ { - 1 }mol−1  .

Accepted Answer

A)  14.9
B)  652
C)  -3.40
D)  -28.5
E)  -1.49 ×  10410 ^ { 4 }104

Question 17

According to the following reaction,how much energy is evolved during the reaction of 32.5 g B2H6 and 72.5 g Cl2? The molar mass of B2H6 is 27.67 g  mol−1\mathrm { mol } ^ { - 1 }mol−1  . B2H6(g) + 6Cl2(g) ? 2BCl3(g) + 6HCl(g)  
DrH° = -1396 kJ

Accepted Answer

A)  1640 kJ
B)  238 kJ
C)  1430 kJ
D)  3070 kJ
E)  429 kJ

Question 18

Which of the following signs on q and w represent a system that is doing work on the surroundings as well as gaining heat from the surroundings?

Accepted Answer

A)  q = +,w = -
B)  q = -,w = +
C)  q = +,w = +
D)  q = -,w = -
E)  None of these represent the system referenced above.

Question 19

Calculate the internal energy change,ΔrU,for the combustion of 6.9261 g of diethylene glycol (C4H10O3,molar mass = 106.120 g mol-1) if the combustion inside a bomb calorimeter,Ccal = 13.84 kJ °C-1,causes a temperature change from 22.8 °C to 34.0 °C.

Accepted Answer

A)  -4.39 × 103 kJ mol-1
B)  -9.16 × 102 kJ mol-1
C)  -2.37 × 103 kJ mol-1
D)  4.39 × 103 kJ mol-1
E)  1.18 × 103 kJ mol-1

Question 20

Define chemical energy.

Accepted Answer

Chemical energy is the energy ...

Exam 6: Thermochemistry

The specific heat capacity of liquid mercury is 0.14 J $g ^ { - 1 }$ $\mathrm { K } ^ { - 1 }$ .How many joules of heat are needed to raise the temperature of 4.00 g of mercury from 19.0°C to 39.5°C?

Correct Answer
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Correct Answer
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Which of the following signs on q and w represent a system that is doing work on the surroundings as well as gaining heat from the surroundings?

Correct Answer
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Correct Answer
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Correct Answer
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Define chemical energy.

Correct Answer
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Chemical energy is the energy ...
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Correct Answer
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Explain the difference between ΔH and ΔU.

Correct Answer
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Change in enthalpy (ΔH)only tracks the e...
View Answer

Correct Answer
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The specific heat capacity of methane gas is 2.20 J $g ^ { - 1 }$ $\mathrm { K } ^ { - 1 }$ .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

Calculate the internal energy change,Δ_rU,for the combustion of 29.3 g of vitamin C (C₆H₈O₆,molar mass = 176.124 g mol^-1) if the combustion inside a bomb calorimeter,C_cal = 8.31 kJ °C^-1,causes a temperature change from 21.5 °C to 68.3 °C.

Correct Answer
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Which of the following statements is TRUE?

Correct Answer
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An unknown metal alloy,specific heat capacity = 0.372 J g^-1 °C^-1,has a temperature change of +21.7 °C after a heat transfer of 216.4 J.Calculate the mass of the alloy in question.

Correct Answer
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Correct Answer
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Calculate the final temperature of 82.1 g of molecular hydrogen (specific heat capacity = 14.304 J g^-1 °C^-1) initially at 5.48 °C that absorbs 57 kJ of energy from the surroundings.

Correct Answer
verified

Calculate the internal energy change,Δ_rU,for the combustion of 6.9261 g of diethylene glycol (C₄H₁₀O₃,molar mass = 106.120 g mol^-1) if the combustion inside a bomb calorimeter,C_cal = 13.84 kJ °C^-1,causes a temperature change from 22.8 °C to 34.0 °C.

Correct Answer
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According to the following reaction,how much energy is evolved during the reaction of 32.5 g B₂H₆ and 72.5 g Cl₂? The molar mass of B₂H₆is 27.67 g $\mathrm { mol } ^ { - 1 }$ . B₂H₆(g) + 6Cl₂(g) ? 2BCl₃(g) + 6HCl(g) D_rH°= -1396 kJ

Correct Answer
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The specific heat of copper is 0.385 J $g ^ { - 1 }$ $\mathrm { K } ^ { - 1 }$ .If 34.2 g of copper,initially at 21.0 °C,absorbs 4.689 kJ,what will be the final temperature of the copper?

Correct Answer
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Correct Answer
verified

A balloon is inflated from 0.0100 L to 0.500 L against an external pressure of 10.00 bar.How much work is done in joules? (100 J = 1 L bar)

Correct Answer
verified

Exam 6: Thermochemistry

The specific heat capacity of liquid mercury is 0.14 J g−1g ^ { - 1 }g−1 K−1\mathrm { K } ^ { - 1 }K−1 .How many joules of heat are needed to raise the temperature of 4.00 g of mercury from 19.0°C to 39.5°C?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following signs on q and w represent a system that is doing work on the surroundings as well as gaining heat from the surroundings?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Define chemical energy.

Correct AnswerverifiedChemical energy is the energy ...View AnswerShow Answer

Correct AnswerverifiedShow Answer

Explain the difference between ΔH and ΔU.

Correct AnswerverifiedChange in enthalpy (ΔH)only tracks the e...View AnswerShow Answer

Correct AnswerverifiedShow Answer

The specific heat capacity of methane gas is 2.20 J g−1g ^ { - 1 }g−1 K−1\mathrm { K } ^ { - 1 }K−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

Calculate the internal energy change,ΔrU,for the combustion of 29.3 g of vitamin C (C6H8O6,molar mass = 176.124 g mol-1) if the combustion inside a bomb calorimeter,Ccal = 8.31 kJ °C-1,causes a temperature change from 21.5 °C to 68.3 °C.

Correct AnswerverifiedShow Answer

Which of the following statements is TRUE?

Correct AnswerverifiedShow Answer

An unknown metal alloy,specific heat capacity = 0.372 J g-1 °C-1,has a temperature change of +21.7 °C after a heat transfer of 216.4 J.Calculate the mass of the alloy in question.

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Calculate the final temperature of 82.1 g of molecular hydrogen (specific heat capacity = 14.304 J g-1 °C-1) initially at 5.48 °C that absorbs 57 kJ of energy from the surroundings.

Correct AnswerverifiedShow Answer

Calculate the internal energy change,ΔrU,for the combustion of 6.9261 g of diethylene glycol (C4H10O3,molar mass = 106.120 g mol-1) if the combustion inside a bomb calorimeter,Ccal = 13.84 kJ °C-1,causes a temperature change from 22.8 °C to 34.0 °C.

Correct AnswerverifiedShow Answer

According to the following reaction,how much energy is evolved during the reaction of 32.5 g B2H6 and 72.5 g Cl2? The molar mass of B2H6 is 27.67 g mol−1\mathrm { mol } ^ { - 1 }mol−1 . B2H6(g) + 6Cl2(g) ? 2BCl3(g) + 6HCl(g) DrH° = -1396 kJ

Correct AnswerverifiedShow Answer

The specific heat of copper is 0.385 J g−1g ^ { - 1 }g−1 K−1\mathrm { K } ^ { - 1 }K−1 .If 34.2 g of copper,initially at 21.0 °C,absorbs 4.689 kJ,what will be the final temperature of the copper?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A balloon is inflated from 0.0100 L to 0.500 L against an external pressure of 10.00 bar.How much work is done in joules? (100 J = 1 L bar)

Correct AnswerverifiedShow Answer

The specific heat capacity of liquid mercury is 0.14 J $g ^ { - 1 }$ $\mathrm { K } ^ { - 1 }$ .How many joules of heat are needed to raise the temperature of 4.00 g of mercury from 19.0°C to 39.5°C?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Chemical energy is the energy ...
View Answer

Correct Answer
verified

Correct Answer
verified
Change in enthalpy (ΔH)only tracks the e...
View Answer

Correct Answer
verified

The specific heat capacity of methane gas is 2.20 J $g ^ { - 1 }$ $\mathrm { K } ^ { - 1 }$ .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

Calculate the internal energy change,Δ_rU,for the combustion of 29.3 g of vitamin C (C₆H₈O₆,molar mass = 176.124 g mol^-1) if the combustion inside a bomb calorimeter,C_cal = 8.31 kJ °C^-1,causes a temperature change from 21.5 °C to 68.3 °C.

Correct Answer
verified

Correct Answer
verified

An unknown metal alloy,specific heat capacity = 0.372 J g^-1 °C^-1,has a temperature change of +21.7 °C after a heat transfer of 216.4 J.Calculate the mass of the alloy in question.

Correct Answer
verified

Correct Answer
verified

Calculate the final temperature of 82.1 g of molecular hydrogen (specific heat capacity = 14.304 J g^-1 °C^-1) initially at 5.48 °C that absorbs 57 kJ of energy from the surroundings.

Correct Answer
verified

Calculate the internal energy change,Δ_rU,for the combustion of 6.9261 g of diethylene glycol (C₄H₁₀O₃,molar mass = 106.120 g mol^-1) if the combustion inside a bomb calorimeter,C_cal = 13.84 kJ °C^-1,causes a temperature change from 22.8 °C to 34.0 °C.

Correct Answer
verified

According to the following reaction,how much energy is evolved during the reaction of 32.5 g B₂H₆ and 72.5 g Cl₂? The molar mass of B₂H₆is 27.67 g $\mathrm { mol } ^ { - 1 }$ . B₂H₆(g) + 6Cl₂(g) ? 2BCl₃(g) + 6HCl(g) D_rH°= -1396 kJ

Correct Answer
verified

The specific heat of copper is 0.385 J $g ^ { - 1 }$ $\mathrm { K } ^ { - 1 }$ .If 34.2 g of copper,initially at 21.0 °C,absorbs 4.689 kJ,what will be the final temperature of the copper?

Correct Answer
verified

Correct Answer
verified

Correct Answer
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