Question 1

A 35.6 g sample of ethanol (C2H5OH) is burned in a bomb calorimeter according to the following reaction. If the temperature rose from 35.0 °C to 76.0°C and the heat capacity of the calorimeter is 23.3 kJ °C-1, what is the value of ΔrU°? The molar mass of ethanol is 46.07 g mol-1. C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(g) ΔrU° = ?

Accepted Answer

A)  -1.24 × 103 kJ mol-1
B)  +1.24 × 103 kJ mol-1
C)  -8.09 × 103 kJ mol-1
D)  -9.55 × 103 kJ mol-1
E)  +9.55 × 103 kJ mol-1

Question 2

The specific heat of copper is 0.385 J g-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 3

Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide according to the chemical equation shown below. When 0.015 mol of Na is added to 100.00 g of water, the temperature of the resulting solution rises from 25.00 °C to 31.45 °C. If the specific heat of the solution is 4.18 J g-1°C-1, calculate ΔH for the reaction, as written. 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g) ΔrH= ?

Accepted Answer

A)  -5.41 kJ
B)  -90.0 kJ
C)  -180 kJ
D)  -360 kJ

Question 4

Calculate the initial temperature of 21.8 g of lithium (specific heat capacity = 3.582 J g-1 °C-1) that absorbs 1642 J of energy from the surroundings and has a final temperature of 31.08 °C.

Accepted Answer

A)  52.11 °C
B)  38.04 °C
C)  26.74 °C
D)  10.05 °C
E)  3.17 °C

Question 5

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 ΔrH°, in units of kJ 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 6

Match the following.

--w

Accepted Answer

A)  the system loses thermal energy to the surroundings
B)  work done on the system by the surroundings
C)  energy flows into the system from the surroundings
D)  the system gains thermal energy from the surroundings
E)  energy flows out of the system into the surroundingsF) work done by the system on the surroundings

Question 7

The specific heat capacity of methane gas is 2.20 J g-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)  88.6 J
B)  429 J
C)  1221 J
D)  0.0113 J
E)  22.9 J

Question 8

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)  ΔrU can be determined using constant volume calorimetry.
C)  Energy is neither created nor destroyed, excluding nuclear reactions.
D)  ΔrH can be determined using constant pressure calorimetry.
E)  All of the above are true.

Question 9

A 50.0 g sample of liquid water at 25.0 °C is mixed with 23.0 g of water at 89.0 °C. The final temperature of the water is ________°C.

Accepted Answer

A)  132
B)  27.3
C)  57.0
D)  260
E)  45.2

Question 10

According to the following thermochemical equation, what mass of HF (in g) must react to produce 345 kJ of energy? Assume excess SiO2. SiO2(s) + 4HF(g) → SiF4(g) + 2H2O(l) ΔrH° = -184 kJ

Accepted Answer

A)  42.7 g
B)  37.5 g
C)  150. g
D)  107 g
E)  173 g

Question 11

Identify the major greenhouse gas.

Accepted Answer

A)  CO2
B)  O2
C)  CO
D)  NO
E)  NO2

Question 12

Which of the following statements is TRUE?

Accepted Answer

A)  The burning of fossil fuels contributes to global warming.
B)  Cars that run on hydrogen fuel cells are environmentally friendly.
C)  The more energy produced per kg of CO2 produced, the better the fuel.
D)  Acid rain is one of the problems associated with the combustion of fossil fuels.
E)  All of the above are true.

Question 13

Astatine is an extremely rare element with an estimated 28 g total on Earth. How much energy would be required to heat Earth's entire supply of astatine by 10.0 °C assuming it has a specific heat capacity similar to iodine, 0.214 J g-1 °C-1?

Accepted Answer

A)  60 J
B)  24 J
C)  130 J
D)  14 J
E)  250 J

Question 14

Calculate the work, w, gained or lost by the system when a gas expands from 15 L to 40 L against a constant external pressure of 1.5199 bar.

Accepted Answer

A)  -6.1 kJ
B)  -3.8 kJ
C)  +3.8 kJ
D)  +6.1 kJ

Question 15

Which of the following processes is endothermic?

Accepted Answer

A)  the freezing of water
B)  the combustion of propane
C)  a hot cup of coffee (system) cools on a countertop
D)  the chemical reaction in a "hot pack" often used to treat sore muscles
E)  the vaporization of rubbing alcohol

Question 16

Calculate the final temperature of a 38.1 g piece of graphitic carbon, originally at 100.0 °C, placed inside a coffee cup calorimeter containing 68.0 mL of water at 24.6 °C. The specific heat capacity of water is 4.184 J g-1 °C-1, the specific heat capacity of graphitic carbon is 0.709 J g-1 °C-1, and the density of water is 1.00 g mL-1.

Accepted Answer

A)  14.7 °C
B)  26.8 °C
C)  31.1 °C
D)  28.6 °C
E)  34.0 °C

Question 17

Calculate the initial temperature of 648 g of cucumber (specific heat capacity = 1.88 J g-1 °C-1) that absorbs 19857 J of heat while warming up to room temperature, 24.8 °C.

Accepted Answer

A)  9.62 °C
B)  8.50 °C
C)  10.3 °C
D)  14.8 °C
E)  3.41 °C

Question 18

Define chemical energy.

Accepted Answer

Chemical energy is the energy ...

Question 19

For a particular process that is carried out at constant pressure, q = 145 kJ and w = -35 kJ. Therefore,

Accepted Answer

A)  ΔU = 110 kJ and ΔH = 145 kJ.
B)  ΔU = 145 kJ and ΔH = 110 kJ.
C)  ΔU = 145 kJ and ΔH = 180 kJ.
D)  ΔU = 180 kJ and ΔH = 145 kJ.

Question 20

A sample of copper absorbs 43.6 kJ of heat, resulting in a temperature rise of 75.0 °C. Determine the mass (in kg) of the copper sample if the specific heat capacity of copper is 0.385 J g-1 °C-1.

Accepted Answer

A)  1.51 kg
B)  6.62 kg
C)  1.26 kg
D)  7.94 kg
E)  3.64 kg

Exam 6: Thermochemistry

A 50.0 g sample of liquid water at 25.0 °C is mixed with 23.0 g of water at 89.0 °C. The final temperature of the water is ________°C.

Correct Answer
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Which of the following statements is TRUE?

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Which of the following statements is TRUE?

Correct Answer
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Identify the major greenhouse gas.

Correct Answer
verified

Which of the following processes is endothermic?

Correct Answer
verified

Calculate the work, w, gained or lost by the system when a gas expands from 15 L to 40 L against a constant external pressure of 1.5199 bar.

Correct Answer
verified

The specific heat capacity of methane gas is 2.20 J g^-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 Answer
verified

Correct Answer
verified

Define chemical energy.

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

A sample of copper absorbs 43.6 kJ of heat, resulting in a temperature rise of 75.0 °C. Determine the mass (in kg) of the copper sample if the specific heat capacity of copper is 0.385 J g^-1°C^-1.

Correct Answer
verified

Calculate the initial temperature of 648 g of cucumber (specific heat capacity = 1.88 J g^-1 °C^-1) that absorbs 19857 J of heat while warming up to room temperature, 24.8 °C.

Correct Answer
verified

The specific heat of copper is 0.385 J g^-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 Answer
verified

For a particular process that is carried out at constant pressure, q = 145 kJ and w = -35 kJ. Therefore,

Correct Answer
verified

According to the following thermochemical equation, what mass of HF (in g) must react to produce 345 kJ of energy? Assume excess SiO₂. SiO₂(s) + 4HF(g) → SiF₄(g) + 2H₂O(l) Δ_rH°= -184 kJ

Correct Answer
verified

Calculate the initial temperature of 21.8 g of lithium (specific heat capacity = 3.582 J g^-1 °C^-1) that absorbs 1642 J of energy from the surroundings and has a final temperature of 31.08 °C.

Correct Answer
verified

Match the following. --w

Correct Answer
verified

Astatine is an extremely rare element with an estimated 28 g total on Earth. How much energy would be required to heat Earth's entire supply of astatine by 10.0 °C assuming it has a specific heat capacity similar to iodine, 0.214 J g^-1 °C^-1?

Correct Answer
verified

Exam 6: Thermochemistry

A 50.0 g sample of liquid water at 25.0 °C is mixed with 23.0 g of water at 89.0 °C. The final temperature of the water is ________°C.

Correct AnswerverifiedShow Answer

Which of the following statements is TRUE?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following statements is TRUE?

Correct AnswerverifiedShow Answer

Identify the major greenhouse gas.

Correct AnswerverifiedShow Answer

Which of the following processes is endothermic?

Correct AnswerverifiedShow Answer

Calculate the work, w, gained or lost by the system when a gas expands from 15 L to 40 L against a constant external pressure of 1.5199 bar.

Correct AnswerverifiedShow Answer

The specific heat capacity of methane gas is 2.20 J g-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

Correct AnswerverifiedShow Answer

Define chemical energy.

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

A sample of copper absorbs 43.6 kJ of heat, resulting in a temperature rise of 75.0 °C. Determine the mass (in kg) of the copper sample if the specific heat capacity of copper is 0.385 J g-1 °C-1.

Correct AnswerverifiedShow Answer

Calculate the initial temperature of 648 g of cucumber (specific heat capacity = 1.88 J g-1 °C-1) that absorbs 19857 J of heat while warming up to room temperature, 24.8 °C.

Correct AnswerverifiedShow Answer

The specific heat of copper is 0.385 J g-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

For a particular process that is carried out at constant pressure, q = 145 kJ and w = -35 kJ. Therefore,

Correct AnswerverifiedShow Answer

According to the following thermochemical equation, what mass of HF (in g) must react to produce 345 kJ of energy? Assume excess SiO2. SiO2(s) + 4HF(g) → SiF4(g) + 2H2O(l) ΔrH° = -184 kJ

Correct AnswerverifiedShow Answer

Calculate the initial temperature of 21.8 g of lithium (specific heat capacity = 3.582 J g-1 °C-1) that absorbs 1642 J of energy from the surroundings and has a final temperature of 31.08 °C.

Correct AnswerverifiedShow Answer

Match the following. --w

Correct AnswerverifiedShow Answer

Astatine is an extremely rare element with an estimated 28 g total on Earth. How much energy would be required to heat Earth's entire supply of astatine by 10.0 °C assuming it has a specific heat capacity similar to iodine, 0.214 J g-1 °C-1?

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

The specific heat capacity of methane gas is 2.20 J g^-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 Answer
verified

Correct Answer
verified

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

A sample of copper absorbs 43.6 kJ of heat, resulting in a temperature rise of 75.0 °C. Determine the mass (in kg) of the copper sample if the specific heat capacity of copper is 0.385 J g^-1°C^-1.

Correct Answer
verified

Calculate the initial temperature of 648 g of cucumber (specific heat capacity = 1.88 J g^-1 °C^-1) that absorbs 19857 J of heat while warming up to room temperature, 24.8 °C.

Correct Answer
verified

The specific heat of copper is 0.385 J g^-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 Answer
verified

Correct Answer
verified

According to the following thermochemical equation, what mass of HF (in g) must react to produce 345 kJ of energy? Assume excess SiO₂. SiO₂(s) + 4HF(g) → SiF₄(g) + 2H₂O(l) Δ_rH°= -184 kJ

Correct Answer
verified

Calculate the initial temperature of 21.8 g of lithium (specific heat capacity = 3.582 J g^-1 °C^-1) that absorbs 1642 J of energy from the surroundings and has a final temperature of 31.08 °C.

Correct Answer
verified

Correct Answer
verified

Astatine is an extremely rare element with an estimated 28 g total on Earth. How much energy would be required to heat Earth's entire supply of astatine by 10.0 °C assuming it has a specific heat capacity similar to iodine, 0.214 J g^-1 °C^-1?

Correct Answer
verified