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Why does the temperature of a substance remains constant during a change of state?
Wiki User
∙ 14y ago
When you add heat to ice at zero degrees celsius the energy causes the movement of ice molecules to increase. When the ice molecules get enough energy, their movement causes them to break free of one another and change to a liquid form. When more heat is added the water molecules absorb that energy and move faster, causing an energy and move faster, causing an increase in temperature (an increase in average energy). When the water molecules absorb enough energy (at about a hundred degrees celsius) they are able to change state again froma liquid to a gas (steam).
Wiki User
∙ 14y ago
Wiki User
∙ 15y agoFor a change of state to occur, heat or energy must be supplied, you'll notice when heating a substance, say ethanol which vapourizes at about 298K, that a vapour is forming and the temp. should remain constant, this is because the entire solution must absorb sufficient energy so that it all vapourizes, only at this point can the solution resume a climb in temperature.
Wiki User
∙ 11y agoAs we know that temperature is changed only when kinetic energy of the substance is changed. When substance is changing its state, the kinetic energy of the substance is being used up by the substance. Hence there is no change in temperature.
Wiki User
∙ 14y agoDuring a change of state an amount of energy (termed the latent heat of vapourization for liquid to gas or latent heat of fusion for solid to liquid, and vice versa) is used to reorganize the chemical structure of the molecule. This energy can therfore not be used to increase or decrease the temperature of the substance. Intramolecular an intermolecular bonds must be broken and reformed.
Google "Cooling Curves" to get a basic understanding of this idea. I have not done this myself, but have studied them extensively.
Wiki User
∙ 11y agoYes the temperature remains constant. For example: In the ice the molecules are strongly bonded to one another, thus forming a rigid solid. When heat is added to the ice it melts, and these bonds are broken, The molecules afterward bond to one another with less strength, and water is formed.
Now, before the melting, the molecules were actually moving when in the solid state. They were vibrating back and forth. They had an average kinetic energy. So they had a Kelvin temperature proportional to this average kinetic energy.
After the melting the water molecules are moving, also. And they have the same average kinetic energy as they had before the melting. So, the water is at the same temperature the moment after the melting that the ice was at the moment before the melting.
Heat came into the situation, but it was not used to change the kinetic energy of the molecules. It was used to change the bonding between the molecules. Breaking the bonds between the molecules of the ice requires energy, and this energy is the added heat.
Wiki User
∙ 12y agoassertion invalid, temperatures of substances can change in a reaction.
Anonymous
Because energy is being used to overcome intermolecular forces.
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What happens to a substances temperature during a phase change?
stays the same
Explain why the temperature of Wax remains constant during solidification?
it's because it releases the latent heat of fusion. Latent heat means energy is given out when a substance changes from liquid to solid without a change in temperature. and the transfer of energy doesnt change the KE of the particles, so the temperature remains unchanged. lanten heat gives rise to the change in PE of the particles during the change of state only
As heat is added to a substance undergoing a phase change. why does the temperature remain?
Basically what it comes down to is the substance that is left behind during the phase change (say the liquid when it is changing to a vapor) has a lower internal energy than it had before the phase change started. To maintain the substance at its original temperature, an equivalent amount of energy must be added to make up for the loss of internal energy due to the phase change. (Conservation of Energy)The energy added in this case is heat, which in turn causes more molecules of the substance to change phases and lowers the internal energy & the process repeats. This is why the temperature remains constant as you add heat to a substance during a phase change. Once the phase change is completed the added heat will eventually cause the temperature to rise in the new phase of the substance. Hope this explanation helps. It's kind of hard to explain without a basic knowledge of thermodynamics.
Boiling liquid maintains a constant temperature because?
The boiling point temperature remains constant because liquids evaporate at this point. If the temperature drops the liquid will no longer boil. At a higher temperature the vapor becomes hotter, not the liquid.
Suppose the temperature of the air in a balloon is increased if the pressure remains constant.. what quantity must change Would it be Volume or Number of molecules or Compressibility OR Adhesion?
Volume
What happens to a substance's temperature as it god through the change of state?
Its temperature remains constant.
Does the temperature change while a phase chage is occurring?
No, the temperature does not change during a phase change. It remains constant until all the substance has undergone the phase change.
What happens to a substances temperature during a phase change?
stays the same
As heat is added to a substance undergoing a phase change the temperature remains constant because the energy is being used to?
Overcome intermolecular forces
How does temperature change during change of physical change?
Temperature remains constant during the change in phase (physical state).
What happens to substances temperature during a change of state?
Temperature remains constant
What happens to the speed of a wave of the medium temperature and pressure do not change?
remains constant
Does the temperature of a substance change before the change of state is complete?
No. During a phase change the temperature is constant until the phase change is complete.
What is unique about temperature on a phase change?
The temperature remains constant during the phase change until all of the substance has been changed or converted into the new phase (i.e. solid to liquid). That is because all of the energy going into (being absorbed by) the substance is being applied toward converting the substance into the new phase. At the point that the last entity of the substance has been converted into the new phase and no more of the old phase (solid) remains, the energy absorbed will begin to raise the temperature of the substance.
What During a phase change the temperature of a substance .?
The temperature* remains unchanged. * The heat (energy) content changes.
Ice melts at o degree centigrate the temperature remain constant at o degree centegrate until all the ice has melted suggest why the temperature remains constant during melting although heat is abs?
At melting point of a substance the supplied heat is utilized to change the state so temperature remains constant till all the material is converted into liquid, this is known asLatent heat of fusion.
Does the temperature of a substance changes before the change of state is completed?
No. During a phase change the temperature is constant until the phase change is complete.
