heat transfer through different mediums

[MaxxxRacer]

oh btw, what is the catalyst for the H20 to H30 + -H0.... is it just waters' natural tendency to ionize even when kept pure.

[saratoga]

This is false, no matter how pure the water is, you'll still have a chemical reaction going on which H2O <=> H3O+ + OH-
The concentration of the ion is very small (10^(-14) ) but still existant

Maxxx, yeah i'm quite good at math in general and i had pretty advanced courses

Does self ionization contribute to conductivity though? Seems like as soon as you setup a charge gradient you'd get recombination. I don't know enough to think about this correctly.

[MaxxxRacer]

saratoga, any ionization will make it more conductive. that was kind of his point.

[nebuchanezzar]

Didn't mean to get this going on the conductivity of water . Just impying that having an actual thermal conductivity would vary moreso with water than a metal waterblock or heatsink as those have pretty specific/exact amounts of x metal (97%copper and 3%zinc or something for example). Distilled water is the norm because de-ionized water does have a slighty -(?) ionic charge which is why it is able to absorb/bond with so many other things. I'm just of the opinion that in the quest to get the exchange of heat down that the water is the "larger" variable here. We of course all know that just for the density difference alone it is better than air and a water cooled system returns to idle temps faster than air(usually) but the original question was how well the heat transfers between x and water and x and air.

[MaxxxRacer]

oh thats easy.


its always higher with water... plain and simple.. water has a much higher heat capacity so it just transfer heat better..

[saratoga]

saratoga, any ionization will make it more conductive. that was kind of his point.

On more thought I think you are right. Seems like any EMF would push apart H+/OH-, leading to more ionization and more conduction, not less as I was thinking.

[MaxxxRacer]

oh lol.. i need to relearn my electronegativy values.. its cool that we are actually getting to use chemistry in this stuff. it makes it more fun.

btw, anitpop said it was H3O+ and OH-.. take two water molecles and thats what u get when u split them up. if you did it the way you are saying you would end up getting hydrogen gass spewing out from the water, which would be cool. but albeit incredibly dangerous.

EDIT: btw i know that hydrogen has is H2 and not just H...

[nebuchanezzar]

oh thats easy.


its always higher with water... plain and simple.. water has a much higher heat capacity so it just transfer heat better..

Yes but what I mean is someone can look up Cu..copper in a science book and it will list thermal conductivity, can we look up water also? It's been way too long since I was in school to be trying to rehash chemisty class

sonething like this

[MaxxxRacer]

oh.. lol.. google is your friend, confedon, dictionary, and encyclopedia

[MaxxxRacer]

its 4.184 joules per gram, where as Cu is .385... lol... only about 11 times the heat capacity.. no biggy

[nebuchanezzar]

its 4.184 joules per gram, where as Cu is .385... lol... only about 11 times the heat capacity.. no biggy

Isn't heat capacity how much it holds? I could be wrong but what is the heat transfer. For standing water I would assume its squat compared to moving water as an example jsut like a passive hs doesn't perform for squat compared to the same on w/a friggin tornado blowin thru it. I was under the impression that silver and then copper are the best conductors of heat but like I already said...it's been a long time since I tried to stay awake in school

[MaxxxRacer]

yah im trying to find some information on that. yes specific heat capacity is how much it holds. I would love to find some information on heat transmission rates though.

[saratoga]

oh lol.. i need to relearn my electronegativy values.. its cool that we are actually getting to use chemistry in this stuff. it makes it more fun.

btw, anitpop said it was H3O+ and OH-.. take two water molecles and thats what u get when u split them up. if you did it the way you are saying you would end up getting hydrogen gass spewing out from the water, which would be cool. but albeit incredibly dangerous.

EDIT: btw i know that hydrogen has is H2 and not just H...

Too long since I took AP chem, but as I recall, there are several models of how acid base reactions work. One of them uses Hydronium (H3O+) to hold the proton liberated by ionized water. It doesn't become H2 gas because theres no e- for it to combine with, at least not in pure water. Add an electric current to water and you will get H2 gas bubleing out.

Yes but what I mean is someone can look up Cu..copper in a science book and it will list thermal conductivity, can we look up water also? It's been way too long since I was in school to be trying to rehash chemisty class

You can but its very misleading. Conduction is only one of several ways heat moves through water. There are also various convective effects. I have no idea how to solve them, and from what I've seen of Bill, pH, Les and other's math, its not trivial and involves a lot of intuition backed by experimenting. Theres nothing trivial about fluid dynamics. People get their PHDs doing this kind of stuff.

Isn't heat capacity how much it holds?

Joules of heat held per gram of mass per degree. So temperature difference times specific heat times mass gives the energy in some volume of water. Obviously this is a good thing to have in a coolant since it will mean that each GPH of flow will carry a lot of energy. Lower it and you carry less heat.

Likewise it'll have no effect on solids like copper, because they have 0 flow and rely purely on conduction, which is not dependent on capacity, only conductivity.

[STEvil]

Copper.
You're after the thermal conductivity.
Al 6063-T6 is 200W/m-K
Cu C110 is 388W/m-K
So copper has almost twice the conductivity of Al.
That in turn means it will convect heat better to water or air.

exactly what i'm looking for, thanks!

All the rest of the stuff in this thread is gold too btw

EDIT

Ahh... http://hyperphysics.phy-astr.gsu.edu...les/thrcn.html
Water: http://www.lsbu.ac.uk/water/explan4.html
Conversion tools: http://www.processassociates.com/pro...ert/cf_tcn.htm

[MaxxxRacer]

*steals thread and runs away screaming he has gold*

[nebuchanezzar]

*steals thread and runs away screaming he has gold*

Sneaks up for a drive by muggin

[antipop]

oh lol.. i need to relearn my electronegativy values.. its cool that we are actually getting to use chemistry in this stuff. it makes it more fun.

btw, anitpop said it was H3O+ and OH-.. take two water molecles and thats what u get when u split them up. if you did it the way you are saying you would end up getting hydrogen gass spewing out from the water, which would be cool. but albeit incredibly dangerous.

EDIT: btw i know that hydrogen has is H2 and not just H...

You're absolutely right my equation wasn't balanced
The equation is 2H2O <=> H30+ + OH- (you have 4 H and 2 O on each side )
The way i described it is even cooler, you put one molecule of water and you end up getting twice the amount

This reaction is always happening in the water (it happens in both directions until it reaches an equilibrium)
This is closely related to the pH, calcultated as the concentration of OH- in the water : pH = - log ([H3O+]).
Distilled water as a pH of 7 meaning that [H3O+] = 10^(-7) this is really a tiny amount!

ps : this is only true at 298K, you get more or less reaction as you rise or drop the temperature

[MaxxxRacer]

lol antipop... taking the log of a molecule... thats for next semester for me.

and 298K is relatively the temp that we work in so it applies to us.

[antipop]

lol antipop... taking the log of a molecule... thats for next semester for me.

and 298K is relatively the temp that we work in so it applies to us.

The log of a concentration isn't very hard to get is the concentration is 10^-3 the log will be 3 it's as simple as that (ok not so simple but you'll see)

ps : in what year are you?

[The Mofo]

You guys need to get out and hit some female a$$!!!

[Butcher_]

oh thats easy.

its always higher with water... plain and simple.. water has a much higher heat capacity so it just transfer heat better..

Mainly it's because water has much higher density and is a liquid.

[MaxxxRacer]

lol mofo.. who needs a$$ when u got a cd-rom drive.. just dont tell my gf that

antipop, im second semester, first year.. just starting out. still in 2 dimensional space in physics. no accounting for friction either.

[antipop]

lol mofo.. who needs a$$ when u got a cd-rom drive.. just dont tell my gf that

antipop, im second semester, first year.. just starting out. still in 2 dimensional space in physics. no accounting for friction either.

Then you still have a lot to learn You'll learn a not of useful stuff

Mofo, how much do you usualy pay ?

[Craig]

If still of interest Silver conductivity is 406 IIRC.

So the differnace between silver & copper is relativly small, at least as compared to the differance between copper or silver vs aluminum @ 205.