Calorimetry, Specific Heat, and Calculations - AP Chemistry
Card 1 of 130
How much heat does it take to heat 100g ice at 0C to boiling point?
Cice= 2.1 J/goC
Cwater= 4.2 J/goC
ΔHvap= 2260 J/g
ΔHfus=334 J/g
How much heat does it take to heat 100g ice at 0C to boiling point?
Cice= 2.1 J/goC
Cwater= 4.2 J/goC
ΔHvap= 2260 J/g
ΔHfus=334 J/g
Tap to reveal answer
You need heat for the phase change, using the enthalpy of fusion (100g*334 J/g = 33400 J). Add to this the heat to get to boiling point using the specific heat of water (100g*100C*4.2 J/goC = 42000 J). Totalling 75400 J (75.4 kJ)
You need heat for the phase change, using the enthalpy of fusion (100g*334 J/g = 33400 J). Add to this the heat to get to boiling point using the specific heat of water (100g*100C*4.2 J/goC = 42000 J). Totalling 75400 J (75.4 kJ)
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A 50g sample of a metal was heated to 
then quickly transferred to an insulated container containing 50g of 
at 
. The final temperature of the 
was 
.
Which of the following can be concluded?
A 50g sample of a metal was heated to
Which of the following can be concluded?
Tap to reveal answer
When the heated metal is placed in the container of the cooler water there will be a transfer of thermal energy from the metal to the water. This transfer will occur towards an equilibrium of thermal energy in the water and in the metal. Thus we can conclude that the amount of thermal energy lost by the metal will equal the amount of thermal energy gained by the water. However we notice that the water increases by only 5oC and the metal decreases by 65oC. This is becasue of the difference of the specific heats of these substances. The specific heat capacity of a substance is the heat required to increase the temperature of 1g of a substance by 1oC. The metal can be conluded to have a smaller specific heat than the water because the same amount of energy transfer led to a much larger change in termperature for the metal as compared to the water.
When the heated metal is placed in the container of the cooler water there will be a transfer of thermal energy from the metal to the water. This transfer will occur towards an equilibrium of thermal energy in the water and in the metal. Thus we can conclude that the amount of thermal energy lost by the metal will equal the amount of thermal energy gained by the water. However we notice that the water increases by only 5oC and the metal decreases by 65oC. This is becasue of the difference of the specific heats of these substances. The specific heat capacity of a substance is the heat required to increase the temperature of 1g of a substance by 1oC. The metal can be conluded to have a smaller specific heat than the water because the same amount of energy transfer led to a much larger change in termperature for the metal as compared to the water.
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Which of the following is the correct molar specific heat of water used when making calculations involving a calorimeter?
Which of the following is the correct molar specific heat of water used when making calculations involving a calorimeter?
Tap to reveal answer
4.184 J/gK is the cited value for the specific heat of water and should be memorized. This is used during calorimeter calculations, specifically when using the equation q= mc delta(T).
4.184 J/gK is the cited value for the specific heat of water and should be memorized. This is used during calorimeter calculations, specifically when using the equation q= mc delta(T).
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In which instance would a bomb calorimeter be more useful than a coffee-cup calorimeter?
In which instance would a bomb calorimeter be more useful than a coffee-cup calorimeter?
Tap to reveal answer
Bomb calorimeters are most useful when dealing with a gas, because they can operate well at high pressures. Coffee-cup calorimeters are not useful when water begins to boil, producing vapor.
Bomb calorimeters are most useful when dealing with a gas, because they can operate well at high pressures. Coffee-cup calorimeters are not useful when water begins to boil, producing vapor.
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The specific heat capacity of an unknown liquid is 
. The density of the liquid is 
If a chemist applies 243 J of heat to 300 mL of this liquid starting at 
, what is the final temperature?
The specific heat capacity of an unknown liquid is
Tap to reveal answer
First we will determine the mass of the liquid:
Now we will examine the relationship between heat and specific heat capacity:
Where 
is heat in Joules, 
is the specific heat capacity, 
is the mass and 
is the change in temperature. We can rearrange this
If we begin at 
, we will end at 
First we will determine the mass of the liquid:
Now we will examine the relationship between heat and specific heat capacity:
Where
If we begin at
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The following is a list of specific heat capacities for a few metals.
A 50g sample of an unknown metal is heated with 800 joules. If the temperature of the metal increases by 41.6oC, what is the identity of the unknown metal?
The following is a list of specific heat capacities for a few metals.
A 50g sample of an unknown metal is heated with 800 joules. If the temperature of the metal increases by 41.6oC, what is the identity of the unknown metal?
Tap to reveal answer
We need to find the specific heat of the unknown sample of metal in order to locate it on the list. We can do this by using the equation that allows us to determine the specific heat capacity of an element.
Since we know the change in temperature, we can simply plug in the values and solve for the value of 
.
Going back to the list, we see that this is the specific heat capacity for copper, so we confirm that the unknown metal is copper.
We need to find the specific heat of the unknown sample of metal in order to locate it on the list. We can do this by using the equation that allows us to determine the specific heat capacity of an element.
Since we know the change in temperature, we can simply plug in the values and solve for the value of
Going back to the list, we see that this is the specific heat capacity for copper, so we confirm that the unknown metal is copper.
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A 20g sample of iron at a temperature of 
is placed into a container of water. There are 300 milliliters of water in the container at a temperature of 
.
What is the final temperature of the water?
A 20g sample of iron at a temperature of
What is the final temperature of the water?
Tap to reveal answer
There are two things to note before solving for the final temperature.
1. The density of water allows us to say that 300 milliliters of water is the same thing as 300 grams of water.
2. Since the heat from the iron is being transferred to the water, we can say that the heat transfer is equal between both compounds. Since the heat is conserved in the system, we can set the two equations equal to one another.
Notice how the change in temperature for iron has been flipped in order to avoid a negative number.
Because water has a much higher heat capacity compared to iron, the temperature of the water is not changed significantly.
There are two things to note before solving for the final temperature.
1. The density of water allows us to say that 300 milliliters of water is the same thing as 300 grams of water.
2. Since the heat from the iron is being transferred to the water, we can say that the heat transfer is equal between both compounds. Since the heat is conserved in the system, we can set the two equations equal to one another.
Notice how the change in temperature for iron has been flipped in order to avoid a negative number.
Because water has a much higher heat capacity compared to iron, the temperature of the water is not changed significantly.
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How much energy is needed to raise the temperature of five grams of ice from 
to 
?
How much energy is needed to raise the temperature of five grams of ice from
Tap to reveal answer
This question involves the total energy needed for three different processes: the temperature raise from 
to 
, the melting of the ice, and the temperature raise from 
to 
. For the first and third transitions we will use the equation 
. For the melting of ice, we will use the equation 
.
1. 
2. 
3. 
Finally, we will need to sum the energy required for each step to find the total energy.
This question involves the total energy needed for three different processes: the temperature raise from
1.
2.
3.
Finally, we will need to sum the energy required for each step to find the total energy.
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You want to prepare a cup of tea. To do so, you pour 
of tap water at 
in a cup that does not absorb microwave radiation and heat it in a microwave oven at 
of power. If you assume a density of 
for the water and know that its specific heat capacity is 
, what time do you need to set in the microwave oven to heat the water to 
?
You want to prepare a cup of tea. To do so, you pour
Tap to reveal answer
Since the density of water is 
, the mass of 
is 
. Plug in known values to the equation and solve.
Use the formula below to find the time needed to heat up the sample of water in the microwave:
Our answer must contain three significant figures.
Since the density of water is
Use the formula below to find the time needed to heat up the sample of water in the microwave:
Our answer must contain three significant figures.
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How much heat is needed to raise 
grams of aluminum by 
?
.
How much heat is needed to raise
Tap to reveal answer
To find the amount of heat needed to change the temperature of a given material by a certain amount, we'll need to use the equation for specific heat. The specific heat capacity of a compound represents the amount of energy necessary to raise 
gram of that substance by 
.
To find the amount of heat needed to change the temperature of a given material by a certain amount, we'll need to use the equation for specific heat. The specific heat capacity of a compound represents the amount of energy necessary to raise
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How much heat does it take to heat 100g ice at 0C to boiling point?
Cice= 2.1 J/goC
Cwater= 4.2 J/goC
ΔHvap= 2260 J/g
ΔHfus=334 J/g
How much heat does it take to heat 100g ice at 0C to boiling point?
Cice= 2.1 J/goC
Cwater= 4.2 J/goC
ΔHvap= 2260 J/g
ΔHfus=334 J/g
Tap to reveal answer
You need heat for the phase change, using the enthalpy of fusion (100g*334 J/g = 33400 J). Add to this the heat to get to boiling point using the specific heat of water (100g*100C*4.2 J/goC = 42000 J). Totalling 75400 J (75.4 kJ)
You need heat for the phase change, using the enthalpy of fusion (100g*334 J/g = 33400 J). Add to this the heat to get to boiling point using the specific heat of water (100g*100C*4.2 J/goC = 42000 J). Totalling 75400 J (75.4 kJ)
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A 50g sample of a metal was heated to then quickly transferred to an insulated container containing 50g of at . The final temperature of the was .
Which of the following can be concluded?
A 50g sample of a metal was heated to
Which of the following can be concluded?
Tap to reveal answer
When the heated metal is placed in the container of the cooler water there will be a transfer of thermal energy from the metal to the water. This transfer will occur towards an equilibrium of thermal energy in the water and in the metal. Thus we can conclude that the amount of thermal energy lost by the metal will equal the amount of thermal energy gained by the water. However we notice that the water increases by only 5oC and the metal decreases by 65oC. This is becasue of the difference of the specific heats of these substances. The specific heat capacity of a substance is the heat required to increase the temperature of 1g of a substance by 1oC. The metal can be conluded to have a smaller specific heat than the water because the same amount of energy transfer led to a much larger change in termperature for the metal as compared to the water.
When the heated metal is placed in the container of the cooler water there will be a transfer of thermal energy from the metal to the water. This transfer will occur towards an equilibrium of thermal energy in the water and in the metal. Thus we can conclude that the amount of thermal energy lost by the metal will equal the amount of thermal energy gained by the water. However we notice that the water increases by only 5oC and the metal decreases by 65oC. This is becasue of the difference of the specific heats of these substances. The specific heat capacity of a substance is the heat required to increase the temperature of 1g of a substance by 1oC. The metal can be conluded to have a smaller specific heat than the water because the same amount of energy transfer led to a much larger change in termperature for the metal as compared to the water.
← Didn't Know|Knew It →
Which of the following is the correct molar specific heat of water used when making calculations involving a calorimeter?
Which of the following is the correct molar specific heat of water used when making calculations involving a calorimeter?
Tap to reveal answer
4.184 J/gK is the cited value for the specific heat of water and should be memorized. This is used during calorimeter calculations, specifically when using the equation q= mc delta(T).
4.184 J/gK is the cited value for the specific heat of water and should be memorized. This is used during calorimeter calculations, specifically when using the equation q= mc delta(T).
← Didn't Know|Knew It →
In which instance would a bomb calorimeter be more useful than a coffee-cup calorimeter?
In which instance would a bomb calorimeter be more useful than a coffee-cup calorimeter?
Tap to reveal answer
Bomb calorimeters are most useful when dealing with a gas, because they can operate well at high pressures. Coffee-cup calorimeters are not useful when water begins to boil, producing vapor.
Bomb calorimeters are most useful when dealing with a gas, because they can operate well at high pressures. Coffee-cup calorimeters are not useful when water begins to boil, producing vapor.
← Didn't Know|Knew It →
The specific heat capacity of an unknown liquid is . The density of the liquid is If a chemist applies 243 J of heat to 300 mL of this liquid starting at , what is the final temperature?
The specific heat capacity of an unknown liquid is
Tap to reveal answer
First we will determine the mass of the liquid:
Now we will examine the relationship between heat and specific heat capacity:
Where is heat in Joules, is the specific heat capacity, is the mass and is the change in temperature. We can rearrange this
If we begin at , we will end at
First we will determine the mass of the liquid:
Now we will examine the relationship between heat and specific heat capacity:
Where
If we begin at
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The following is a list of specific heat capacities for a few metals.
A 50g sample of an unknown metal is heated with 800 joules. If the temperature of the metal increases by 41.6oC, what is the identity of the unknown metal?
The following is a list of specific heat capacities for a few metals.
A 50g sample of an unknown metal is heated with 800 joules. If the temperature of the metal increases by 41.6oC, what is the identity of the unknown metal?
Tap to reveal answer
We need to find the specific heat of the unknown sample of metal in order to locate it on the list. We can do this by using the equation that allows us to determine the specific heat capacity of an element.
Since we know the change in temperature, we can simply plug in the values and solve for the value of .
Going back to the list, we see that this is the specific heat capacity for copper, so we confirm that the unknown metal is copper.
We need to find the specific heat of the unknown sample of metal in order to locate it on the list. We can do this by using the equation that allows us to determine the specific heat capacity of an element.
Since we know the change in temperature, we can simply plug in the values and solve for the value of
Going back to the list, we see that this is the specific heat capacity for copper, so we confirm that the unknown metal is copper.
← Didn't Know|Knew It →
A 20g sample of iron at a temperature of is placed into a container of water. There are 300 milliliters of water in the container at a temperature of .
What is the final temperature of the water?
A 20g sample of iron at a temperature of
What is the final temperature of the water?
Tap to reveal answer
There are two things to note before solving for the final temperature.
1. The density of water allows us to say that 300 milliliters of water is the same thing as 300 grams of water.
2. Since the heat from the iron is being transferred to the water, we can say that the heat transfer is equal between both compounds. Since the heat is conserved in the system, we can set the two equations equal to one another.
Notice how the change in temperature for iron has been flipped in order to avoid a negative number.
Because water has a much higher heat capacity compared to iron, the temperature of the water is not changed significantly.
There are two things to note before solving for the final temperature.
1. The density of water allows us to say that 300 milliliters of water is the same thing as 300 grams of water.
2. Since the heat from the iron is being transferred to the water, we can say that the heat transfer is equal between both compounds. Since the heat is conserved in the system, we can set the two equations equal to one another.
Notice how the change in temperature for iron has been flipped in order to avoid a negative number.
Because water has a much higher heat capacity compared to iron, the temperature of the water is not changed significantly.
← Didn't Know|Knew It →
How much energy is needed to raise the temperature of five grams of ice from to ?
How much energy is needed to raise the temperature of five grams of ice from
Tap to reveal answer
This question involves the total energy needed for three different processes: the temperature raise from to , the melting of the ice, and the temperature raise from to . For the first and third transitions we will use the equation . For the melting of ice, we will use the equation .
1.
2.
3.
Finally, we will need to sum the energy required for each step to find the total energy.
This question involves the total energy needed for three different processes: the temperature raise from
1.
2.
3.
Finally, we will need to sum the energy required for each step to find the total energy.
← Didn't Know|Knew It →
You want to prepare a cup of tea. To do so, you pour of tap water at in a cup that does not absorb microwave radiation and heat it in a microwave oven at of power. If you assume a density of for the water and know that its specific heat capacity is , what time do you need to set in the microwave oven to heat the water to ?
You want to prepare a cup of tea. To do so, you pour
Tap to reveal answer
Since the density of water is , the mass of is . Plug in known values to the equation and solve.
Use the formula below to find the time needed to heat up the sample of water in the microwave:
Our answer must contain three significant figures.
Since the density of water is
Use the formula below to find the time needed to heat up the sample of water in the microwave:
Our answer must contain three significant figures.
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How much heat is needed to raise grams of aluminum by ?
.
How much heat is needed to raise
Tap to reveal answer
To find the amount of heat needed to change the temperature of a given material by a certain amount, we'll need to use the equation for specific heat. The specific heat capacity of a compound represents the amount of energy necessary to raise gram of that substance by .
To find the amount of heat needed to change the temperature of a given material by a certain amount, we'll need to use the equation for specific heat. The specific heat capacity of a compound represents the amount of energy necessary to raise
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