GRE Subject Test: Chemistry : Heat and Temperature

Example Questions

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Example Question #63 : Biochemistry, Organic Chemistry, And Other Concepts

Use the following values for water as needed.

If burning wood releases  of heat energy per gram of wood consumed, what mass of wood must be consumed to heat  of water from  to , and then to convert it to water vapor?

Explanation:

There are two processes requiring added heat in this problem:

1. Raising the temperature of the liquid water from  to  (use )

2. Boiling the water at a constant temperature of  (use )

To use either of these equation, we need to find the mass of the water using the relation between mass, density, and volume.

Use this mass with the given specific heat and temperatures to find the heat for part 1 of the process.

Then, use the mass with the given heat of vaporization to find the energy needed to convert the water to water vapor.

Sum the energies for step 1 and step 2.

This is the total amount of energy needed from the burning wood. Use stoichiometry to find the grams of wood needed to produce this amount of energy.

Example Question #1 : Heat And Temperature

What was the final temperature of water if a  sample of water absorbs  of heat energy and heats up from ? (specific heat of water is )

Explanation:

Specific heat is the amount of heat needed to raise 1 gram of a substance by 1oC. Calorimeters used for these types of experiments because they are designed to be well-insulated, so no heat is gained from or lost to the surroundings.

Example Question #2 : Heat And Temperature

An  metal at  was put into  of water at . The final temp of the water and metal was . Assuming heat was not lost to the surroundings find the specific heat of the metal? The specific heat of water is .

Explanation:

Specific heat is the amount of heat needed to raise 1 gram of a substance by 1oC. Calorimeters used for these types of experiments because they are designed to be well-insulated, so no heat is gained from or lost to the surroundings.

Heat is transferred from the metal to the water.

Example Question #361 : Gre Subject Test: Chemistry

Calculate the final temperature when a  sample of metal (specific heat of the metal=) at  is placed into  of water at . (specific heat of water is )

Explanation:

Specific heat is the amount of heat needed to raise 1 gram of a substance by 1oC. Calorimeters used for these types of experiments because they are designed to be well-insulated, so no heat is gained from or lost to the surroundings.

Heat is transferred from the metal to the water.

Example Question #3 : Heat And Temperature

Calculate the specific heat of  of metal that requires  of heat energy to raise its temperature from  to ?

Explanation:

Specific heat is the amount of heat needed to raise 1 gram of a substance by 1oC. Calorimeters used for these types of experiments because they are designed to be well-insulated, so no heat is gained from or lost to the surroundings.

Example Question #4 : Heat And Temperature

What was the final temperature of the water if a  sample of water absorbs  of heat energy and heats up from ? (specific heat of water is )

Explanation:

Specific heat is the amount of heat needed to raise 1 gram of a substance by 1oC. Calorimeters used for these types of experiments because they are designed to be well-insulated, so no heat is gained from or lost to the surroundings.

Rearranging gives,

Example Question #364 : Gre Subject Test: Chemistry

A  metal at  was placed in  of water at . The final temp of the water and metal was . Assuming heat was not lost to the surroundings find the specific heat of the metal? The specific heat of water is .

Explanation:

Specific heat is the amount of heat needed to raise 1 gram of a substance by 1oC. Calorimeters used for these types of experiments because they are designed to be well-insulated, so no heat is gained from or lost to the surroundings.

Heat is transferred from the metal to the water.

Example Question #5 : Heat And Temperature

What was the final temperature of the water if a  sample of water absorbs  of heat energy and heats up from ? (specific heat of water= )

Explanation:

Specific heat is the amount of heat needed to raise 1 gram of a substance by 1oC. Calorimeters used for these types of experiments because they are designed to be well-insulated, so no heat is gained from or lost to the surroundings.

Rearranging gives,

Example Question #366 : Gre Subject Test: Chemistry

A  metal at  was placed in  of water at . The final temp of the water and metal was . Assuming heat was not lost to the surroundings find the specific heat of the metal? The specific heat of water is .

Explanation:

Specific heat is the amount of heat needed to raise 1 gram of a substance by 1oC. Calorimeters used for these types of experiments because they are designed to be well-insulated, so no heat is gained from or lost to the surroundings.

Heat is transferred from the metal to the water.

Example Question #6 : Heat And Temperature

How much heat is absorbed when  of water goes from  to ? (Specific heat of water= )