Science question!
<div class="IPBDescription">Kemistrie</div>So like, I need some other peoples opinion on whether Im right on this or not. I cook ramen, frequently. I like ramen. Now, I always put the stove on "High" so that the water gets to boil faster (When a man needs his ramen he needs it NOW). However, my parents mentioned at some point that I shouldn't put the stove on high, because it is likely to burn the pan (Apparently it was written as a warning on some new set of pans we bought). They said that I should only put it on med-high, since that is still hot enough to make it boil. Now with my extensive (read: not really) chemistry knowledge, I think they are wrong about this. According to my understanding of chemical phase changes, when the chemical is undergoing a phase change (In this case, the water turning to steam) that the chemical will not change temperature past the temp required for the phase change. So, what Im trying to say is that, while the stove is capable of heating to 500 degrees or something (Which is hot enough to damage the coatings on the bottom of the pan) once the water starts boiling, it will remain at 212 F, hence the pan will remain at 212 F, and not be burnt. However, once all the water evaporates into a gas, then it will begin heating past 212 F.
am i rite?
am i rite?
Comments
1: When anything undergoes a phase change, the item in question doesn't magically stop getting hotter, as there is a constant amount of energy being transferred into the ambience around it. Now, unless that energy constant is at a perfect equilibrium with the temperature of the item in question at the state it is in, then the water will continue to get hotter, until the heat lost by the steam is the same as the heat energy coming in, from the pan.
2:What your parents mean by "burning the pan", is that having too high a heat, and no moisure on the opposing surface will degrade the non-stick surface, imparing the efficiency. Tell them that you're boiling water, and that unless the entire pan is dry, and still being heated, that the pan will not, in fact, "burn"...
Non stick frying pans are VERY different then conventional cookware. Their nonstick coating is a plastic compound, and while it can conduct high heats, it will melt and damage the cookware long before anything actually happens to the metal.
It's true that liquid water can't be heated past one hundred degrees. Water can of course be heated past one hundred degrees, but at that point it ceases to be liquid. The liquid in the pan will remain at boiling temperature, one hundred degrees.
However, it is true that the pan will be hotter than this because heat is applied to the bottom of it. However, the pan is probably made of aluminium or cast iron, both of which are very good heat conductors. This serves to decrease the temperature difference of different parts of the pan as heat is quickly transferred from hotter to colder areas in accordance with the second law of thermodynamics. So while the bottom of the pan will be hotter, it won't be by a very large measure.
What you need to be careful of is fat and oils, since these reach much higher temperatures than water does.
Personally, I think that there still is a reason to change the stove's temperature to med-high rather than high after a while of cooking (I'm going to go a little off topic here). Once the water hits 100 degrees celsius, it will continue to be 100 degrees until it hits the gas stage (as said before me). So, there is no reason to keep it at high because the only result would be more evaporation and more energy consumption.
Also, if you use the old style stoves with the spiny things that get hot (forgot its name) and put it to high, it apparently damages the spiny thing (when it gets to the point where the spiny thing becomes red, the damage starts). So rather than damaging the pan itself, your damaging the thing that heats the pan.
I'm not sure if this is true or not, my 66 year old dad told me both of these 2 facts in a story.
P.S: I think that putting it to high can damage the pan in some way. I have a pan in my house that has lasted a long time (30 years maybe) of being used almost daily and with the stove on high, and now its deformed a little. But its nothing too serious, just a few minor bumps which cause some hot spots and a darkened bottom, thats pretty much it. I very much doubt that anyone in my family got mad and beat up the pan to that point <img src="style_emoticons/<#EMO_DIR#>/tounge.gif" style="vertical-align:middle" emoid=":p" border="0" alt="tounge.gif" />, as what happened to my globe awhile ago (there is a hole in North America now <img src="style_emoticons/<#EMO_DIR#>/tounge.gif" style="vertical-align:middle" emoid=":p" border="0" alt="tounge.gif" /> ).
P.P.S: I R no scientist, so I'm probably wrong.
You can't burn a pot that is in the process of boiling water on a conventional stove. They are designed a little more intellegently then that. Furthermore, even if you burn a normal kettle to hell (leave it on over night), it's just stainless steel, it doesn't undergo a chemical change when it is heated unless you get it past the liquification point, which is isn't possible on a conventional stove top because it will short out first. The kettle will discolor and look ugly, but it won't do any actual damage to the kettle.
Non stick frying pans are VERY different then conventional cookware. Their nonstick coating is a plastic compound, and while it can conduct high heats, it will melt and damage the cookware long before anything actually happens to the metal.
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<img src="style_emoticons/<#EMO_DIR#>/wow.gif" style="vertical-align:middle" emoid=":0" border="0" alt="wow.gif" /> People still use non-electric kettles?
As for the actual chemistry...
The process is somewhat demonstrated by filling a paper cup with water and then holding a lit match up to the cup. The thermal conductivity of your cookware needs to be taken into consideration however; while metal and glass can usually transfer the heat quickly they still have a decent amount of thickness (unlike the paper cup), and the temperature next to the burner isn't going to be the same as the side heating the water. Plastic coatings and such usually can't take such extreme heats - but I've never seen a pot for boiling water with a teflon coating. Despite all that, also remember that air pressure and water quality can have an impact on the temperature your water attains before evaporating and could potentially heat the cookware hotter than you intend. Also, many people add salt to their water when boiling noodles (and some other things), which increases the boiling temperature.
<!--quoteo--><div class='quotetop'>QUOTE</div><div class='quotemain'><!--quotec-->1: When anything undergoes a phase change, the item in question doesn't magically stop getting hotter, as there is a constant amount of energy being transferred into the ambience around it. Now, unless that energy constant is at a perfect equilibrium with the temperature of the item in question at the state it is in, then the water will continue to get hotter, until the heat lost by the steam is the same as the heat energy coming in, from the pan.<!--QuoteEnd--></div><!--QuoteEEnd-->
And Patch, the water does maintain a constant temperature while the water prepares to evaporate...it takes extra energy for phase changes (<a href="http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/phase.html" target="_blank">phase changes</a> a quick and dirty internet search). This means the water maintains its 212 degrees Fahrenheit or 100 degrees celsius or whatever average kinetic energy (again, adjustfor air pressure and impurities) while boiling, and the temperature only gets hotter once the water is steam. So it doesn't 'magically' stop getting hotter, it has a reason for doing so <img src="style_emoticons/<#EMO_DIR#>/biggrin-fix.gif" style="vertical-align:middle" emoid=":D" border="0" alt="biggrin-fix.gif" /> .
Water is one of the coolest chemicals. High specific heat (and heat of vaporization/fusion), abundance allows for a use as our standard for computing volume and mass, suface tension due two magnetic interaction of the hydroxide polyatmoic ion, the fact that it consist of H and OH essentially means it is an acid and a base (coincidentally whenever an acid and a base are combined they form water and a salt - unlike Bart's experiments in a certain Simpsons episode), ease of forming solutions, lack of electrical conductivity (in distilled water) - also the cool ability to become superheated. The list continues...heck, who doesn't love water?
...except for those crazy <a href="http://en.wikipedia.org/wiki/Hydrophobia" target="_blank">hydrophobics</a>...
Just buy a cheap stainless steel/glass Ramen-cooking pot; then you don't need to cross the potential of damaging expensive cookware coatings.
You can't burn a pot that is in the process of boiling water on a conventional stove. They are designed a little more intellegently then that. Furthermore, even if you burn a normal kettle to hell (leave it on over night), it's just stainless steel, it doesn't undergo a chemical change when it is heated unless you <b>get it past the liquification point, which is isn't possible</b> on a conventional stove top because it will short out first. The kettle will discolor and look ugly, but it won't do any actual damage to the kettle.
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that, my good sir, is where you are dead wrong.
all started with boiling water for mac & cheese, and forgetting about it for 2 hours. i smelled smoke and ran out to check it, lifted the lid and only saw bright red metal. so i turned off the stove and moved the pot to another burner, then looked back at the first burner and the bottom of the pot was still there.
This problem is easily solved by simply filling a ceramic bowl with water and heating it in the microwave...once it's warm, throw the ramen block in, breaking it until you can submerge it all, and then heating it some more. Your noodles will be noodly, and it doesn't take nearly as long as it does to boil water. Hopefully you have a bowl capable of holding enough water and a block/cracked block of noodles...<!--QuoteEnd--></div><!--QuoteEEnd-->
I don't like microwaved ramen. For some reason, it just doesn't taste right to me.
youre partially right. when the water reaches 212 it will remain at 212 until it is in gas form, but the pan is not undergoing a phase change so it will continue to rise past 212. in fact, the pan would most likely be well past 212 before the water even starts boiling since the pan is a better conductor than water is. when you start seeing the bubbles on the bottom of the pan that is when the pan is hot enough to make the water boil, but the majority of the water is not hot enough, so in essence the water at the bottom of the pan is boiling while water at the top is not.
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This man is correct. However, all of this is pretty much useless as I doubt you could do any real damage in the 5-10 minutes it's taking you to make your ramen, hell, even if you leave it on for 15-20. I'm guessing it would probably take at least 20-30 minutes to do serious damage to the pan/etc.
This man is correct. However, all of this is pretty much useless as I doubt you could do any real damage in the 5-10 minutes it's taking you to make your ramen, hell, even if you leave it on for 15-20. I'm guessing it would probably take at least 20-30 minutes to do serious damage to the pan/etc.
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Actually there is a problem in the arguement. Yes, the water heats slower then the pan. It doesn't change the fact that the water will, however, continue to cool the pan. Since we came to the conclusion that the water will not heat past 212 F, then it will continue to absorb heat from the pan, thus limiting the overall temperature of the pan as well.
Actually there is a problem in the arguement. Yes, the water heats slower then the pan. It doesn't change the fact that the water will, however, continue to cool the pan. Since we came to the conclusion that the water will not heat past 212 F, then it will continue to absorb heat from the pan, thus limiting the overall temperature of the pan as well.
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but the since the pan heats up faster than the water, the water can only absorb heat at a certain rate, which is slower than the pan. so the pan absorbs heat faster than the water, thus heating it up to temperatures of higher than 212.
and i guess going back to theoriginal question, the pan isnt going to get a huge deal higher than 212, and it most likely will not burn. your parents are probably worried about the nonstick on the pan, which will be fine as long as water is in it as previously stated. so in essence you and your parents are both wrong, but you still win.
I don't know much about all this science mumbo-jumbo, but aren't we discussing physics and not chemistry?
and I had no idea people still boiled water for ramen on a stove. that totally defeats the purpose of an instant food, you might as well cook real food <img src="style_emoticons/<#EMO_DIR#>/sad-fix.gif" style="vertical-align:middle" emoid=":(" border="0" alt="sad-fix.gif" />
lastly, people allege that you can't burn a pot if there's water in it - well, I have a couple pots that I've never done anything but boil water for pasta in, and I've probably eaten most of the teflon or whatever from the bottom of em, cuz it sure as hell ain't still on the bottom of the pots...