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Post by Andrew on Aug 24, 2013 19:56:46 GMT
Nautonnier you are muddled up. A child can understand the topic, no PhD is required Lets have a look at what you wrote for 14-15 year olds. If you have a large 3 dimensional lattice with weak bonds as the energy is supplied it increases the vibrational energy of the molecules but not the kinetic energy (temperature) of the volume containing molecules.the kinetic energy of the vibrational movement is essentially the temperature so you are mixed up there. There is not a special kind of kinetic energy in the way you are suggesting that separately creates temperature.Eventually the vibrations are such that some of the lattice bonds break.
no problem with that.This is the change of state when there are insufficient lattices absorbing energy Again this is the bit you are muddled up on, the increases in the vibrations is the absorbed heat so that eventually the hydrogen bonding that was present before is no longer possible and the more chaotic next phase is enabled where the freer molecules can only exist while they have not lost the energy of movement that we call heat, and therefore it requires what we call heat to break them free from the previously more highly ordered structure. to keep the overall kinetic energy of the molecules low the average kinetic energy of the molecules -the temperature- starts increasing.
This is totally muddled up The molecules that are not in a lattice (liquid) are now closer together and therefore the liquid is denser than the ice state. Water is loosely hydrogen bonded compared to ice which is more highly orderedThe molecules of water are continually trying to coalesce into a lattice due to the hydrogen bonds - but at temperatures (kinetic energy levels) above freezing these bonds are breaking as fast or faster than they form. yes As water cools the reverse takes place and the conservation of energy laws mean that the kinetic energy is radiated as heat energy as the water molecule lattice forms. The kinetic energy of waters vibrations is the heat. To get ice to form, that kinetic energy has to be removed by the presence of something colder that the water can radiate to or be in contact with.
There is no spare heat that gets beamed out of the water to warm the atmosphere other than the heat that 0C water has that can warm -10C air.
You obviously have knowledge but even so you are muddled up.Iceskater - you seem to delight in trying to split hairs in non-formal descriptions. Fine. That is not the point of this forum. Your initial claim was that "no energy was released" on state change condensing or freezing. The references I provided show that you are WRONG. I suggest that you go to some of the simple sites set up for elementary and middle school children and read them. You will then find that the state change DOES indeed liberate energy. Obfuscating your mistake by 'clever comments' does not win any points. Listen pal. I am not obfuscating and i strongly object to the lie that i am obfuscating. Freezing water can only heat the object that is cooling the freezing water. There is no liberated energy available to raise the temperature of the other objects once freezing begins that was not already available in the water before freezing began, I have attempted to educate on this subject and if you dont like my style well that is the style i have Obviously you are muddled and obviously that is the way it is going to stay. |
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Post by Andrew on Aug 24, 2013 19:59:25 GMT
Latent heat of Fusion is kinetic energy. It is the active vibrational movement of water that has to be removed to enable a more rigid less vibrationally active structure to form. The energy is removed by cooling. It cannot heat anything other than whatever is causing the cooling. There is a difference between vibrational energy while still held in a crystal lattice and the kinetic energy of a free molecule with its own separate velocity vector. Until you understand that point you will not understand latent heat. There is no difference. They are both heat. But the freer molecule has a vibrational energy that has to be removed for the more ordered phase to exist. |
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Post by Andrew on Aug 24, 2013 20:12:57 GMT
Nautonnier you are muddled up. A child can understand the topic, no PhD is required Lets have a look at what you wrote for 14-15 year olds. If you have a large 3 dimensional lattice with weak bonds as the energy is supplied it increases the vibrational energy of the molecules but not the kinetic energy (temperature) of the volume containing molecules.the kinetic energy of the vibrational movement is essentially the temperature so you are mixed up there. There is not a special kind of kinetic energy in the way you are suggesting that separately creates temperature.Eventually the vibrations are such that some of the lattice bonds break.
no problem with that.This is the change of state when there are insufficient lattices absorbing energy Again this is the bit you are muddled up on, the increases in the vibrations is the absorbed heat so that eventually the hydrogen bonding that was present before is no longer possible and the more chaotic next phase is enabled where the freer molecules can only exist while they have not lost the energy of movement that we call heat, and therefore it requires what we call heat to break them free from the previously more highly ordered structure. to keep the overall kinetic energy of the molecules low the average kinetic energy of the molecules -the temperature- starts increasing.
This is totally muddled up The molecules that are not in a lattice (liquid) are now closer together and therefore the liquid is denser than the ice state. Water is loosely hydrogen bonded compared to ice which is more highly orderedThe molecules of water are continually trying to coalesce into a lattice due to the hydrogen bonds - but at temperatures (kinetic energy levels) above freezing these bonds are breaking as fast or faster than they form. yes As water cools the reverse takes place and the conservation of energy laws mean that the kinetic energy is radiated as heat energy as the water molecule lattice forms. The kinetic energy of waters vibrations is the heat. To get ice to form, that kinetic energy has to be removed by the presence of something colder that the water can radiate to or be in contact with.
There is no spare heat that gets beamed out of the water to warm the atmosphere other than the heat that 0C water has that can warm -10C air.
You obviously have knowledge but even so you are muddled up.Iceskater - you seem to delight in trying to split hairs in non-formal descriptions. Fine. That is not the point of this forum. Your initial claim was that "no energy was released" on state change condensing or freezing. The references I provided show that you are WRONG. I suggest that you go to some of the simple sites set up for elementary and middle school children and read them. You will then find that the state change DOES indeed liberate energy. Obfuscating your mistake by 'clever comments' does not win any points. The mature thing to do is deal with the reasonably detailed points i raised in reply to your points, where i pointed out you were confused in specific areas, rather than being abusive so you can ignore what i have told you. Directing me to sites created for children when i am a 57 year old chemistry graduate *and* you have declined to tell me what your qualifications are *and* you have failed to satisfactorly answer the points i put to you suggests you are not willing to learn. |
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Post by numerouno on Aug 24, 2013 20:31:10 GMT
I do know that when sprinkling water on orchards etc, the insulation value of the ice is used to help, but the heat released when forming that ice is the primary source of warmth to keep the orchard from freezing for short periods of time. No! Latent heat can never be used for any real-life heating or cooling purpose under no circumstances. Your comparison to potential energy is wrong, as potential energy can be increased/released at will. You can elevate a stone, and drop it at any time from any height. Not so with the phase change energies. They are bound into the molecular forces of the matter and are forces that will ONLY DELAY changes in the temperature of the matter AS LONG AS THE PHASE CHANGE GOES ON! Your orchard water will DELAY the freezing while the freezing is ongoing, but WILL RELEASE NO ENERGY WHATSOEVER WHILE DOING SO! Feeel free to consider this at your leisure. |
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Post by Andrew on Aug 24, 2013 20:39:58 GMT
No! Latent heat can never be used for any real-life heating or cooling purpose under no circumstances. Thats not really so true. Evaporation of water into dry warm air cools the air. Our hot sweaty skin is cooled by evaporation into a dryer environment. A dehumidifier warms the air by removing water. A fohn wind is hot and dry These things however require work. Eg dry air has to be created by some force somewhere to enable cooling to occur later, or moist air has to be cooled by some force and then warmed by some force, for a zero sum action that condenses water, to enable warming to occur. |
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Post by numerouno on Aug 24, 2013 20:56:26 GMT
Yes, I in fact told you just the other day these people here each have their respective versions of the laws of physics that they will also defend to to last person standing.
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Post by Andrew on Aug 24, 2013 21:01:40 GMT
Yes, I in fact told you just the other day these people here each have their respective versions of the laws of physics that they will also defend to to last person standing. I suppose we can all get like that a bit. I wonder if you will recognise that an ice breaker needs to be enormously strong in its ability to resist the crushing force that has two vectors that arises from the practice of ramming? Realisticly you are never going to concede on that for at least the next ten years until you are approaching 60 and you have the same view of 40 as i have. Then there was all that 18m Sampo nonesense. What was that all about? |
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Post by numerouno on Aug 24, 2013 21:05:14 GMT
A dehumidifier warms the air by removing water. Oh no, no more miracle devices, please! This seems to be a myth originating from the English. If you count in the energy used to cool down the unit vs any heat gained by doing so, your heat budget will be on the red. Another device in fact that we northerners could use as a free energy heating source, were it for real. |
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Post by Andrew on Aug 24, 2013 21:09:11 GMT
A dehumidifier warms the air by removing water. Oh no, no more miracle devices, please! This seems to be a myth originating from the English. If you count in the energy used to cool down the unit vs any heat gained by doing so, your heat budget will be on the red. Another device in fact that we northerners could use as a free energy heating source, were it for real. Quite clearly a fohn wind is a hot dry wind arising from a colder wetter wind What you are probably forgetting is that a dehumidifer passes the wet air thru the cold evaporator and then thru the warm condensor so that the air has a zero sum action performed upon it but it does lose water vapour and losing the water vapour meant that heat had to be extracted and it must have gone somewhere and cannot all be in the cooler water collecting below the evaporator The energy of the sun is required to get an unlimited amount of humid water for a dehumidifier to get 'free' energy from. Not much different to a heat pump |
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Post by magellan on Aug 24, 2013 21:25:32 GMT
I do know that when sprinkling water on orchards etc, the insulation value of the ice is used to help, but the heat released when forming that ice is the primary source of warmth to keep the orchard from freezing for short periods of time. No! Latent heat can never be used for any real-life heating or cooling purpose under no circumstances. Your comparison to potential energy is wrong, as potential energy can be increased/released at will. You can elevate a stone, and drop it at any time from any height. Not so with the phase change energies. They are bound into the molecular forces of the matter and are forces that will ONLY DELAY changes in the temperature of the matter AS LONG AS THE PHASE CHANGE GOES ON! Your orchard water will DELAY the freezing while the freezing is ongoing, but WILL RELEASE NO ENERGY WHATSOEVER WHILE DOING SO! Feeel free to consider this at your leisure. Freezing of water is a release of heat. No dead body required. Before digging your hole deeper arguing with a farmer, you probably should have done a bit more reading on the subject. is.gd/sPBCAT |
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Post by Andrew on Aug 24, 2013 21:31:57 GMT
No! Latent heat can never be used for any real-life heating or cooling purpose under no circumstances. Your comparison to potential energy is wrong, as potential energy can be increased/released at will. You can elevate a stone, and drop it at any time from any height. Not so with the phase change energies. They are bound into the molecular forces of the matter and are forces that will ONLY DELAY changes in the temperature of the matter AS LONG AS THE PHASE CHANGE GOES ON! Your orchard water will DELAY the freezing while the freezing is ongoing, but WILL RELEASE NO ENERGY WHATSOEVER WHILE DOING SO! Feeel free to consider this at your leisure. Freezing of water is a release of heat. No dead body required. Before digging your hole deeper arguing with a farmer, you probably should have done a bit more reading on the subject. is.gd/sPBCATOne nation without a brain indivisible under God |
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Post by magellan on Aug 24, 2013 21:43:58 GMT
Whatever Iceskater said, I'm sure it was contributing to the discussion with respect and continuation of demonstrating his vast knowledge of physics, probably agreeing with Numerouno's educating Sigurdur in the field of Agriculture. I think in this case I'll cast my vote with Sigurdur and nautonnier. www.wvu.edu/~exten/infores/pubs/ageng/sw4.pdf |
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Post by numerouno on Aug 24, 2013 22:49:10 GMT
Freezing of water is a release of heat. No dead body required. Before digging your hole deeper arguing with a farmer, you probably should have done a bit more reading on the subject. Well, I have lived surrounded by freezing and melting water all my life, and I can guarantee there is absolutely no change in temperature when everything freezes up around me! No puffs of warm air, no puffs of cold air, just the same 0C! Show me the free energy from freezing! Any video will do, but, there has to be a thermometer that rises when something freezes close to it! And I must add I'm not expecting any to show up! |
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Post by icefisher on Aug 24, 2013 23:05:27 GMT
numerouno said: "And as I said, the cooling is caused by the expanding water vapour carrying heat away. Were there no carrying away, there would only be a zero-sum phase change at where the water originates." Ok, but the phase change from water vapor to water is a contraction, not an expansion which happens when water turns to vapor. We have to be clear that when water boils a huge amount of energy is added to the water via flame or hot metal to cause the phase change but we do not see a temperature change during the phase change, but we do produce vast amounts of hot steam spreading everywhere in proportion to the heat supplied to the water Then when water is cooled a huge amount of energy has to pass from the water to the cold atmosphere. Ie you are witnessing what happens when you have a force that can cause cooling. Without the cooling force the ice cannot form. So to boil water you need massive heating lets say and massive amounts of hot steam becomes present everywhere. No cooling becomes visible anywhere To freeze water you need massive cooling, you get massive amounts of cold ice everywhere and no massive heating becomes visible The latent heat of evaporation of water just means you have to supply more heat when you boil water and produce lots of hot steam The latent heat of fusion of water just means that when you cool water you need to supply more cooling to produce lots of ice than if the latent heat had a lower value. Nice thought experiment but does not explain the process. "Cooling force" control is just the sort of artificial concept you typically make up to spin your arguments. Freezing is an exothermic release of heat rather than an isothermic process. Exothermic means its akin to an explosion and is not a cooling process. (as a chemist you should know about exothermic processes). An exothermic process can occur spontaneously. The melting of ice is yet another process called endothermic. Endothermic processes do not occur spontaneously but require work from the external environment. Now that does not answer any questions. Work is required to get heat into water, and exothermic process is not limited to normal cooling to get it out as there is a natural attraction force to bind molecules together it takes work to separate them in the form of kinetic energy, no external work is required to get it back out. So you cannot just run a thought experiment by drawing analogies to endothermic or isothermic processes. Very clearly freezing disrupts the cooling paths available. The freezing of ice and release of heat from the water can fill inversion layers. This is true because there is always forces in place to eliminate these inversions. Wind and diffusion are the two most recognized ones. And really the only thing maintaining the inversion is the rapid heat loss of the surface. So whether the heat comes from the ice or from the atmosphere above really doesn't matter the result is the same and its triggered by the freezing of the ice.  Bottom line as Nautonnier suggests a few clever comments does not negate the fact that the release of latent energy is not hidden and is observable and measurable and results in a considerably warmer system without a change in enthalpy. |
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Post by nonentropic on Aug 24, 2013 23:11:37 GMT
Firstly the temperature affect due to water misted into low humidity air is a red herring that's related to vapor pressures etc. A whole new discussion.
Release of energy is what happens when there is a temperature delta. The falling temperature item sheds energy, (release) I entirely agree as we see latent energy released from water at freezing it only shows itself as a temperature buffer so flatlining the temperature at freezing point but no clouds of heat.
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