zking786

What's the exposed element electric kettle? Also, why would you say that it's impractical?

Also, thanks for the clarification silkworm. So voltage does affect electrolysis, by determining the speed at which the "amount of a substance" is produced. So, then the amount of hydrogen produced in a set time is determined by BOTH voltage and current (basically power). So, why would you prefer a low voltage high current set up? If this works simillarly to power, why wouldn't you be able to use high voltage low current to produce the same amount of hydrogen?

That's what I thought, but YT2095 said it'll only sublime and then reform Carbon again--it won't combine with anything else. Any ideas?

I've been told that this method is "pollution free". There can't be ANY carbon monoxide. How could I test for CO? Also, I though (from a few other posts) that carbon will sublime and then go back to its solid state (not bonding with any thing). I'm starting to become confused. The mechanism seems to be what you're describing.The rods are completing a circuit and touching, generating a very high temperature where we can notice lots of underwarer sparks and bubbling. Why can't this be precisely predicted?

B U M P -- Anyone still here?

After reading and attempting to comprehend the site on Faraday's Laws, I had one question. By Faraday's first law, the amount of a substance produced (I'd say hydrogen, in this case) is proportional to the quantity of electricity (Q in coulombs). Since the quantity of electricity is determined by current and time, it seems voltage is inconsequential. Please correct me if I'm wrong (which I probably am), but does that mean I could produce a large amount of hydrogen using a small amount of power. That just doesn't seem to make sense. Can someone explain Faraday's laws in terms of voltage?

I guess it could be that hot? I'd need to do some thermodynamics to find out. Too bad I don't know anything about heat transfer and don't have the apparatus at hand. But, it is clear that the carbon is disappearing from the rod. I didn't notice any carbon residue in the container, wonder what's happening?

Interesting, so either I would get carbon or an alotrope of carbon in the mixture--not CO2 or CO. I can't detect anything in the container after the process is complete, though. Also, what temperature do you think Carbon (or this alotrope used for welding) would sublime at?

YT2095: I think it is "arc welding without the welding", but am not sure since it's completing a circuit. silkworm: Okay, I won't use AC. Anyone know why, though? Also, it is completing a circuit and in doing so it does noticably consume the carbon rod. Within about 15 minutes, the carbon rod is almost completely consumed (8-10in). Here's a background on my research. I'm trying to inexpensively and efficiently produce hydrogen (for use in combustion). Technique 1: The first technique (using a carbon welding rod to arc with a carbon disc or another carbon rod underwater) was recommended by a friend who knew someone who was able to produce large amounts of hydrogen efficiently. I've seen a prototype for this machine and noted the design of the apparatus. It consists of a large tank of water (1ft^3) and a pair of electrodes which are connected to a source of emf (car battery in this case). These electrodes are touching and DO complete a circuit. When the circuit is complete, one notices large underwater sparks and bubbling. Eventually, the carbon welding rods are consumed and the reaction concludes. Throughout the process, hydrogen is definitely produced (vapor is a result when the gas is mixed with air). Carbon dioxide might be produced, as the gas derived by the experiment is NOT combustible on its own. Anyway, the closed reaction chamber (in this case a fish tank) does not heat up significantly probably due to the localized heat in a large chamber of water. I'm wondering, firstly, what the process is called. I still am unsure as to whether it's electrolysis, since you don't need an electrolyte solution and you actually connect the two electrodes together. Some have told me it's the heat (from the short circuit) that separates the water, causing the carbon to bind with oxygen to form carbon dioxide, while liberating hydrogen. Technique 2: I only briefly discussed this technique, as I have only heard of it's viability. It discusses a simillar procedure, except using aluminum rods. I was told that the heat liberates the hydrogen and causes the melted aluminum to form an oxide with oxygen. While I have not tried this method, early experimenters seem to have had some sucess with it. For this experiment, the same questions I had for Technique 1 apply. Also, I was wondering why aluminum and whether it relates to the "melting point" of aluminum. How does this work? Hope this is enough clarification. Thanks for all the responses. It really does help.

Thanks for the informative response. I thought electrolysis wouldn't apply since the electrodes are actually touching (not close together actually touching). Also, I assume it's an allotrope of carbon, since it is a physical rod. It's the type of carbon rod used in welding. You discuss not using AC voltage, why? I read in a booklit on arcing (with carbon rods) that one could use either AC or DC. Why do you mention Edison? I haven't conducted the experiment with AC (only DC), but don't see why AC wouldn't work. I have produced hydrogen, for sure. I'm confident that I did not produce oxygen, since the gasses produced will not combust without additional air. I know the byproduct of the combustion is emmision-less water. As a result, I believe it's producing H2 and possibly CO2. Also, the carbon wasn't melted, it probably sublimed. Why do you mention using an inert electrode? I want something that will react with the oxygen to form an oxide or some gas that won't affect combustion. Lastly, thanks for all your information! I will check out the site on Faraday's laws and will research electroplating. Btw: I am a first-year chemistry student. I've only taken a Chem 101 course at my local Junior College.

Simply stated, I'm wondering how could I derive a position vs. time graph? What would the equation be? How would I take both relativity and the gravitational laws into account and compute the two differential equations?

The temperature is supposed to be very high, causing Carbon to sublime (I think forming CO2, but I'm not sure). As stated, the temperature of the water in the container is room temp and the pressure is 1 ATM. For more details on my experimentation see this thread: http://www.scienceforums.net/forums/showthread.php?t=17238

Maybe the carbon is subliming? All I know is that the electrode is consumed (relatively rapidly) in the process and there is no precipitation. The end result is a H2 and no O2--that's why I'm assuming CO2 is formed. But why would it be considered electrolysis if the electrodes are touching? Also, what about for aluminum? Surely it can't be called electrolysis, since I'm told that the temperature is causing the aluminum to melt. Also, I'm told in the reaction with aluminum that a precipitate (an oxide of aluminum) is formed along with hydrogen gas. Regarding the equations, I'm refering to thermodynamics equations that would apply here and how I'd use them.

The universal gravitation law makes sense, but how do we use calculus to say... graph the equation or find the position data? How does this take relativity into account? Any idea on how we could use differential equations to compute?

While we are told that g = 9.81 m/s/s, this is only an approximation and isn't necessarily always true when we do precise calculations. Since, by the Universal Gravitation Laws, acceleration is determined by the mass of each object and the distance between the objects, we can't necessarily use a "fixed" gravitational acceleration of 9.81, since as we are free-falling gravity's acceleration changes as a function of distance. In fact, even mass changes as we accelerate. I've always wondered how we could compute the true free-fall for an object of mass m as it falls. Any ideas?

While we are told that g = 9.81 m/s/s, this is only an approximation and isn't necessarily always true when we do precise calculations. Since, by the Universal Gravitation Laws, acceleration is determined by the mass of each object and the distance between the objects, we can't necessarily use a "fixed" gravitational acceleration of 9.81, since as we are free-falling gravity's acceleration changes as a function of distance. In fact, even mass changes as we accelerate. I've always wondered how we could compute the true free-fall for an object of mass m as it falls. Any ideas?

Interesting, why does lime water turn white in the presence of CO2? Also, to answer silkworm's question, I don't have many reagents at home. The process is, I'm melting a carbon rod in water by passing lots of current through it. The result is H2 and I'm not sure if CO2 is a byproduct, since I don't think O2 is and there doesn't seem to be any solid precipitation.

I have heard about the separation of water into hydrogen and oxygen underwater by short circuiting a charge. The process uses most metals (I've heard of aluminum and carbon as common) as electrodes. One touches the two electrodes together underwater and applies a current through the two electrodes (either DC or AC). If there's enough power, the electrodes will spark and bubbling will proceed. I've done the reaction with carbon rods and have produced hydrogen alone. It seems the oxygen might have combined with the carbon which was melted to form CO2 (I'm not exactly sure whether this is happening). The discoveries have led me to the following questions: 1. What is this process called and how is it occuring? 2. I've been told the metals (carbon in this case) are "melting" at around 2000 Degrees Celsuis. Is this true? Is there a chart that discusses the melting temperatures of various metals? 3. How can I determine which metals will "melt" most readily to absorb the oxygen and liberate the hydrogen? 4. How can I measure, quantitaitively, the amount of energy being consumed in the various components of the reactions? From a thermodynamics standpoint, I can measure the total amount of energy inputed, but how can I calculate the amount of energy utilized in melting the metal? How much is utilized by heat, by spark, etc.? 5. Is it necessary for both electrodes to be composed of the decided metal? Can I use one of carbon and one that is less consumable? 6. What equations would enable me to deduct the amount of current and charge necessary for differing metals of varying sizes. I would greatly appreciate your assistance in my research. Also, please try to keep explanations basic when possible (I am a HS student ). Thanks!

This is probably a very elementary question, but I was wondering how one could (relatively inexpensively and with everyday items) test for the presence of carbon dioxide in a chamber. More importantly, is there a way I could quantify the amount of CO2 in the chamber? I'm doing an experiment and want to see if CO2 is a byproduct, so I should be able to tell whether the concentration of CO2 has increased by the end of the experiment, so the pressure or volume of CO2 isn't necessary.

There are different sized infinities. For example infinity divided by infinity is not 1; it is undefined.

I thought carbon electrodes and platinum electrodes last long? Also, is the energy stored more in the H-H bonds or in the C-H bonds

I know a friend who has built a simillar model with carbon electrodes. The products are Carbon, Hydrogen, and Oxygen and are used to fuel an engine.

But they reference to a site where they actually power a generator with the produced gas. What do you suggest it is?

Does that generate hydrogen fast? Forgive me for my basic questions, but how would I create an alloy that has NaOH and Al?

If you see this site, their method of electrolysis generates COH2 (not CH2O). http://www.blazelabs.com/pics/coh2-1.jpg