Question 1

Imagine a sample of water vapor at 150°C.List three possible components of a molecule's total kinetic energy.What happens to the average kinetic energy of the molecules if the temperature is doubled?

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Question 2

You wish to devise a way to use wave power to heat water.You determine that approximately 108 kJ of energy are available per second from 3.0-m waves coming in along the coastline.How long would you have to collect energy from the wave in order to heat 18 kg of water from 20.0 °C to 100.0 °C? Assume you can transfer the stored wave energy completely to the water with no energy loss.[c_p(water)= 4.18 J/(g . °C)]

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Question 3

When one mole of potassium chlorate dissolves in a kilogram of water to produce about a liter of solution,the temperature decreases by almost 9°C.Is the dissolution of KClO₃ in water exothermic or endothermic? Briefly explain your answer.

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Question 4

Give a brief description of pressure-volume work.

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Question 5

Suppose the heating curve below is for water initially at -150°C.Describe what is happening or what process is occurring in each region (I,II,III,IV,and V)as heat is added at a constant rate.

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Question 6

A gas contained in a cylinder with a movable piston undergoes the following two changes: (a)It does 2260 J of work on the surroundings while absorbing 4230 J of heat.(b)1950 J of work is done on the gas while it releases 3920 J of heat.What is its total change of internal energy?

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Question 7

A system is compressed from 40.0 L to 22.4 L at a constant pressure of 10.5 atm.Calculate work in joules.

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Question 8

Suppose 250 g of water at 95°C is put in a 486 g stainless steel cup at 25°C.What is the final equilibrium temperature? Assume heat is exchanged only between the water and the cup.[c_p,water = 4.18 J/(g . °C); c_p,stainless steel = 0.49 J/(g . °C)]

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Question 9

A sample of propane gas is contained in a cylinder with a movable piston.The gas undergoes combustion,releasing 22.0 kJ of heat and expanding from 12.0 L to 24.0 L under a constant external pressure of 14.8 atm.Calculate the total change in the energy of the surroundings.

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Question 10

Explain what is meant by the term state function,and give an example of something that is a state function and something that is not a state function.

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Question 11

The molar heat capacities of zinc,titanium,and iron are 25.3,25.0,and 25.1 J/(mol . °C),respectively.What are their specific heat capacities?

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Question 12

Ammonium nitrate (80.04 g/mol)decomposes at high temperatures to form nitrogen,oxygen,and water vapor.Suppose 750 grams decomposes at 350°C and 0.98 atm,generating gases that expand by about 960 L.How much P-V work is done? What is the approximate change in internal energy ($\Delta$E )of the reaction system? (1 L . atm = 101.3 J) NH₄NO₃(s)$\to$ N₂(g)+ O₂(g)+ H₂O(g) $\Delta$H =-118 kJ/mol

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Question 13

In an experiment,36.0 grams of ice at -40.0°C are converted to steam at 180.0°C.About how many kilojoules of energy are required for this process? [$\Delta$H_vap = 2260 J/g; $\Delta$H_fus = 334 J/g; c_p(ice)= 2.06 J/(g . °C); c_p(water)= 4.18 J/(g . °C); c_p(steam)= 1.99 J/(g . °C)]

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Question 14

Describe the difference between the change in the internal energy ($\Delta$E )of a system and the change in enthalpy ($\Delta$H).Begin your description with the definition of enthalpy.

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Question 15

When one mole of potassium hydroxide dissolves in a kilogram of water to produce about a liter of solution,the temperature increases by almost 13°C.Is the dissolution of KOH in water exothermic or endothermic?

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Question 16

If steam expands in the cylinder of a steam engine and does 750 J of work on the surroundings and simultaneously there is 250 J of energy transferred into the steam from the surroundings,what is the change in energy of the steam?

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Question 17

Label the following as exothermic or endothermic. (a)water evaporating from a puddle (b)ammonium nitrate dissolving in an instant cold pack (c)solid CO₂ subliming at room temperature (d)bromine vapor condensing as a liquid on a cold surface

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(a)water...

Question 18

A gas contained in a cylinder with a movable piston does 554 J of expansion work on the surroundings while gaining 977 J of thermal energy.What is the change in internal energy of the gas?

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Question 19

A hot cup of coffee (the system)produces 70 kJ as it cools.What is the change in energy of the system? Of the surroundings? Of the universe? Include signs in your answers.

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Question 20

During the expansion of steam inside the cylinder of a steam engine,the piston moves and the volume of the cylinder increases by 45 mL.The external pressure is a constant 4.0 atm.Calculate the change in the energy of the steam caused by doing this work.

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Quiz 9: Thermochemistry-Energy Changes in Chemical Reactions

Imagine a sample of water vapor at 150°C.List three possible components of a molecule's total kinetic energy.What happens to the average kinetic energy of the molecules if the temperature is doubled?

When one mole of potassium chlorate dissolves in a kilogram of water to produce about a liter of solution,the temperature decreases by almost 9°C.Is the dissolution of KClO₃ in water exothermic or endothermic? Briefly explain your answer.

Give a brief description of pressure-volume work.

Suppose the heating curve below is for water initially at -150°C.Describe what is happening or what process is occurring in each region (I,II,III,IV,and V)as heat is added at a constant rate.

A gas contained in a cylinder with a movable piston undergoes the following two changes: (a)It does 2260 J of work on the surroundings while absorbing 4230 J of heat.(b)1950 J of work is done on the gas while it releases 3920 J of heat.What is its total change of internal energy?

A system is compressed from 40.0 L to 22.4 L at a constant pressure of 10.5 atm.Calculate work in joules.

Suppose 250 g of water at 95°C is put in a 486 g stainless steel cup at 25°C.What is the final equilibrium temperature? Assume heat is exchanged only between the water and the cup.[c_p,water = 4.18 J/(g . °C); c_p,stainless steel = 0.49 J/(g . °C)]

A sample of propane gas is contained in a cylinder with a movable piston.The gas undergoes combustion,releasing 22.0 kJ of heat and expanding from 12.0 L to 24.0 L under a constant external pressure of 14.8 atm.Calculate the total change in the energy of the surroundings.

Explain what is meant by the term state function,and give an example of something that is a state function and something that is not a state function.

The molar heat capacities of zinc,titanium,and iron are 25.3,25.0,and 25.1 J/(mol . °C),respectively.What are their specific heat capacities?

In an experiment,36.0 grams of ice at -40.0°C are converted to steam at 180.0°C.About how many kilojoules of energy are required for this process? [ $\Delta$ H_vap = 2260 J/g; $\Delta$ H_fus = 334 J/g; c_p(ice)= 2.06 J/(g . °C); c_p(water)= 4.18 J/(g . °C); c_p(steam)= 1.99 J/(g . °C)]

Describe the difference between the change in the internal energy ( $\Delta$ E )of a system and the change in enthalpy ( $\Delta$ H).Begin your description with the definition of enthalpy.

When one mole of potassium hydroxide dissolves in a kilogram of water to produce about a liter of solution,the temperature increases by almost 13°C.Is the dissolution of KOH in water exothermic or endothermic?

If steam expands in the cylinder of a steam engine and does 750 J of work on the surroundings and simultaneously there is 250 J of energy transferred into the steam from the surroundings,what is the change in energy of the steam?

Label the following as exothermic or endothermic. (a)water evaporating from a puddle (b)ammonium nitrate dissolving in an instant cold pack (c)solid CO₂ subliming at room temperature (d)bromine vapor condensing as a liquid on a cold surface

A gas contained in a cylinder with a movable piston does 554 J of expansion work on the surroundings while gaining 977 J of thermal energy.What is the change in internal energy of the gas?

A hot cup of coffee (the system)produces 70 kJ as it cools.What is the change in energy of the system? Of the surroundings? Of the universe? Include signs in your answers.

During the expansion of steam inside the cylinder of a steam engine,the piston moves and the volume of the cylinder increases by 45 mL.The external pressure is a constant 4.0 atm.Calculate the change in the energy of the steam caused by doing this work.

Quiz 9: Thermochemistry-Energy Changes in Chemical Reactions

Imagine a sample of water vapor at 150°C.List three possible components of a molecule's total kinetic energy.What happens to the average kinetic energy of the molecules if the temperature is doubled?

When one mole of potassium chlorate dissolves in a kilogram of water to produce about a liter of solution,the temperature decreases by almost 9°C.Is the dissolution of KClO3 in water exothermic or endothermic? Briefly explain your answer.

Give a brief description of pressure-volume work.

Suppose the heating curve below is for water initially at -150°C.Describe what is happening or what process is occurring in each region (I,II,III,IV,and V)as heat is added at a constant rate.

A gas contained in a cylinder with a movable piston undergoes the following two changes: (a)It does 2260 J of work on the surroundings while absorbing 4230 J of heat.(b)1950 J of work is done on the gas while it releases 3920 J of heat.What is its total change of internal energy?

A system is compressed from 40.0 L to 22.4 L at a constant pressure of 10.5 atm.Calculate work in joules.

Suppose 250 g of water at 95°C is put in a 486 g stainless steel cup at 25°C.What is the final equilibrium temperature? Assume heat is exchanged only between the water and the cup.[cp,water = 4.18 J/(g . °C); cp,stainless steel = 0.49 J/(g . °C)]

A sample of propane gas is contained in a cylinder with a movable piston.The gas undergoes combustion,releasing 22.0 kJ of heat and expanding from 12.0 L to 24.0 L under a constant external pressure of 14.8 atm.Calculate the total change in the energy of the surroundings.

Explain what is meant by the term state function,and give an example of something that is a state function and something that is not a state function.

The molar heat capacities of zinc,titanium,and iron are 25.3,25.0,and 25.1 J/(mol . °C),respectively.What are their specific heat capacities?

In an experiment,36.0 grams of ice at -40.0°C are converted to steam at 180.0°C.About how many kilojoules of energy are required for this process? [ Δ\DeltaΔ Hvap = 2260 J/g; Δ\DeltaΔ Hfus = 334 J/g; cp(ice)= 2.06 J/(g . °C); cp(water)= 4.18 J/(g . °C); cp(steam)= 1.99 J/(g . °C)]

Describe the difference between the change in the internal energy ( Δ\DeltaΔ E )of a system and the change in enthalpy ( Δ\DeltaΔ H).Begin your description with the definition of enthalpy.

When one mole of potassium hydroxide dissolves in a kilogram of water to produce about a liter of solution,the temperature increases by almost 13°C.Is the dissolution of KOH in water exothermic or endothermic?

If steam expands in the cylinder of a steam engine and does 750 J of work on the surroundings and simultaneously there is 250 J of energy transferred into the steam from the surroundings,what is the change in energy of the steam?

Label the following as exothermic or endothermic. (a)water evaporating from a puddle (b)ammonium nitrate dissolving in an instant cold pack (c)solid CO2 subliming at room temperature (d)bromine vapor condensing as a liquid on a cold surface

A gas contained in a cylinder with a movable piston does 554 J of expansion work on the surroundings while gaining 977 J of thermal energy.What is the change in internal energy of the gas?

A hot cup of coffee (the system)produces 70 kJ as it cools.What is the change in energy of the system? Of the surroundings? Of the universe? Include signs in your answers.

During the expansion of steam inside the cylinder of a steam engine,the piston moves and the volume of the cylinder increases by 45 mL.The external pressure is a constant 4.0 atm.Calculate the change in the energy of the steam caused by doing this work.

When one mole of potassium chlorate dissolves in a kilogram of water to produce about a liter of solution,the temperature decreases by almost 9°C.Is the dissolution of KClO₃ in water exothermic or endothermic? Briefly explain your answer.

Suppose 250 g of water at 95°C is put in a 486 g stainless steel cup at 25°C.What is the final equilibrium temperature? Assume heat is exchanged only between the water and the cup.[c_p,water = 4.18 J/(g . °C); c_p,stainless steel = 0.49 J/(g . °C)]

In an experiment,36.0 grams of ice at -40.0°C are converted to steam at 180.0°C.About how many kilojoules of energy are required for this process? [ $\Delta$ H_vap = 2260 J/g; $\Delta$ H_fus = 334 J/g; c_p(ice)= 2.06 J/(g . °C); c_p(water)= 4.18 J/(g . °C); c_p(steam)= 1.99 J/(g . °C)]

Describe the difference between the change in the internal energy ( $\Delta$ E )of a system and the change in enthalpy ( $\Delta$ H).Begin your description with the definition of enthalpy.

Label the following as exothermic or endothermic. (a)water evaporating from a puddle (b)ammonium nitrate dissolving in an instant cold pack (c)solid CO₂ subliming at room temperature (d)bromine vapor condensing as a liquid on a cold surface