Change of Phase and Latent Heat

In summary, the temperature will not increase when water changes to steam or ice at their respective critical points because all the energy from the heat source is used to either break or form bonds between the molecules, rather than increasing the temperature. This can be applied to any state change of a substance.
  • #1
Soaring Crane
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0
I am trying to word this question as best as I can.

Once water has reached its bottom-notch state/position, will the temperature increase?

I mean, if water changes to steam once heat is added, why won't the temp. increase (or stay constant)?

Another question is why won't the temp. rise if heat is added to ice when 0 degrees Celsius is reached?

Thanks again, and I'm sorry if I worded this confusingly.
 
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  • #2
The answer to your question is that ( for ice let's say ) if the temp is below 0 degrees celsius then all of the energy from the heat source is going into raising the temperature ( ie magnifying the vibrations of the water molecules ) however once 0 degrees is reached the molecules obtain enough energy to break free from each other, that is all the energy from the heat source goes into breaking the IMF between them, so in a sense the temp doesn't increase because all of the energy goes into breaking the bonds between the molecules. Once all of the molecules have broken free ie: ice into water, the temp will continue to increase.
 
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  • #3
What about the first scenario with steam?

Did I word it incorrectly?
 
  • #4
The same argument goes only now the "before" state and "after" state has changed ( ie water to steam ) as well as the critical temp. Once the temp at which water boils (100 deg Cel. ) is reached, All the energy provided by the source of heat goes into changing the state of the substance, ie: breaking the bonds completely between the water molecules thus forming a gas. Thus this argument can be applied to ANY state change of the substance,,,, the temp rises, then at the critcal point whether its the MP, BP, FP, or whatever the energy goes into the formation/breakage of bonds.
 
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Related to Change of Phase and Latent Heat

1. What is a change of phase and how does it occur?

A change of phase refers to the physical transformation of a substance from one state to another, such as from a solid to a liquid or from a liquid to a gas. This occurs when the substance is heated or cooled to a specific temperature known as its melting point or boiling point, respectively.

2. What is latent heat and how does it relate to a change of phase?

Latent heat is the energy required to change the phase of a substance without changing its temperature. During a change of phase, the energy that is absorbed or released is known as latent heat. This energy is used to break the bonds between particles in a substance, allowing them to change their arrangement and form a different phase.

3. What factors affect the amount of latent heat required for a change of phase?

The amount of latent heat required for a change of phase depends on the type of substance, the initial and final states of the substance, and the pressure at which the change of phase occurs. For example, substances with stronger intermolecular forces will require more energy to change their phase compared to substances with weaker intermolecular forces.

4. Can a substance change phase without a change in temperature?

Yes, a substance can change phase without a change in temperature. This is known as a phase transition and occurs when the energy being absorbed or released is used to break or form bonds between particles, rather than increasing or decreasing the temperature of the substance.

5. How does the concept of latent heat play a role in everyday life?

The concept of latent heat is important in many everyday applications, such as cooking and refrigeration. For example, when water is heated in a pot, the energy absorbed is used to break the bonds between water molecules and change the water from a liquid to a gas (steam). Similarly, in refrigerators, the energy released when a substance changes from a gas to a liquid (condensation) is used to cool the inside of the fridge.

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