zking786

I've used eFunda.com It has some good tutorials and generally provides consistent and reliable information.

Wow, thanks for all the information and guidance. Though it doesn't make complete sense (probably due to my inexperience), I at least now understand the complexity of the reactions and the gist of the processes that are occuring. While I'm reperforming the NaOH experiment, I'll try to wear gloves and goggles. It didn't occur to me that the fats of my skin could be undergoing suponification. I guess that's why it felt a bit smooth. Luckily, though, I didn't get any burns and washed the areas where I felt a tingling sensation. When reperforming the experiment, how would you recommend I deal with any NaOH accidents? Would putting dilute acid (N/10 HCl) on affected areas work?

Could you post the reaction equation for the Al + HCl + CuSO4, for clarity. The balanced equations make the reactions seem so much simpler. So, is the murky solution and the black-coated aluminum the NaAlO2 and AlCl3 from the reactions?

That's interesting... So the hydrogen produced is from the hydrogen in NaOH? I thought it was from the water in the NaOH solution. Also, is the Na in ionic or elemental form (does it gain an electron in the mentioned reaction)? Are you sure that your reaction is correct? I've heard of Al forming a compound with an OH group, not an oxide.

Thanks for that explanation. It makes sense now. So, what happens in the NaOH reaction?

So what exactly is being used up? Is it the HCl or the Al. From your previous response, it seems that the CuSO4 is a catalyst (and is therefore not being consumed). If I wanted to produce hydrogen constantly, how would you reccommend I proceed. What should be added to the mixture? I've got a cooling setup in place, so that won't be a problem.

I've done both experiments and find the 10% HCl+CuSO4+Al to work best. I have some questions, though. 1. What is the brown-black residue? 2. What does the CuSO4 do? 3. Why does the reaction slow down even when I add more Al? It only seems to speed back up when I add 10% HCl. I thought HCl was a catalyst.

I touched my NaOH-water mixture and it wasn't that bad. Initially, I couldn't really feel anything. Later, it burned a bit and I had to wash it with water, soap, and N/10 HCl. It still feels a bit powdery, so I might still have some on my hands.

Maybe if I had raised the lighter a bit higher, I would have had a high enough oxygen concentration to ignite the hydrogen?

Interestingly, when I did the NaOH experiment, it got hot (warmer than I'm comfortable touching), but not "very hot". Is this normal? Why wouldn't hydrogen in excess NOT ignite? Not enough oxygen around it to create an explosion?

I've continued my hydrogen production experimentation, and am now re-trying some of the techniques I've been told... 1. Mix NaOH and Al foil in water to produce hydrogen gas. Unfortunately, though I get rapid bubbling (some times even minor explosion when contained), I can't ignite the produced bubbles. I'm using a gas-stove lighter and I can't even hear the slightest 'pop'. What could be going wrong? 2. I was told that HCl + Al in water will produce hydrogen gas. Is this true? It doesn't make sense to me. Should it, or do I have to add CuSO4 or CuCl to the mixture? Also, I've been wondering how I can remove the oxide coating that forms on Al. If I could, perhaps, recoat it with something that dissolves in water, but prevents the formation of an oxide on the surface, then I could create a non-corrosive, safe hydrogen-production setup.

I'm unaware of any studies which suggest that lack of sleep can lead to brain damage. While many types of psychologists have investigated sleep, their results are far from conclusive. I am pretty sure that lack of sleep does NOT kill neurons.

I know, which is why none of this makes sense. Since the generator definitely can't be 30,000W or 30W, I'm just messing around with numbers. Any ideas? Is this a standard system for specifying the power? I would have expected watts or some measure of max current draw.

Back to the stick example... What if we had the system set up so that the long rod was held in a hinge set up by a long rod of great strength. ______ | | | --------------------------- When we drop the rod, assuming the mass increases infinitely, wouldn't the rod exceed the speed of light? In this case, the infinitely increasing mass aids in the rotation. Am I missing something?

I'm looking to buy a generator. At the store, the guy (who barely speaks English) tells me that the generator is 30kV. I'm wondering what this equates to in terms of watts. Do I divide by 120/240V?

That's odd, cause I see lots of mosquitoes around my tube lights. What type of AC voltage is necessary to kill the bugs? How much current should the transformer be able to handle?

Is this AC or DC voltage? How high is the voltage? Doesn't the bug (even after death) conduct if it's stuck to the close wires, wouldn't this be a short?

It's an old stereo, so I'm wondering if there's another IC with the same specs but a different part number. Also, it would cost a lot to get the part from the manufacturer because they will charge me to import the part from the US and then charge me to ship it internationally. Not to mention the overpricing of the part and the time it will take to import it. So it would be impractical to get it from the service store.

I'm repairing a stereo and it seems an integrated circuit is damaged. I'm trying to replace it, but can't find the circuit in stores. It says (BA6191 345 111). I'm wondering if there's an alternate IC that can be used which can fulfill the same purpose. Perhaps there's another IC with the same specs but another part number?

I've seen lots of these used to kill mosquitoes in the night. Since they are attracted to the light, they approach the light and are zapped. Any idea how these devices work? I'm trying to build one.

Perhaps it uses energy from an electrostatic field that's setup in an area? For example, if you have a Van De Graaf on and hold a tube light a distance from it, in a position such that that the tube is on a radius of the sphere of the Van De Graaf, you can light the tube up based on the potential difference between the ends of the tube. Perhaps it's something like that?

Are you trying to say that soap, or any other solute, when added to the water mixture, will decrease the surface tension? Is this because the cohesive forces of the water decrease due to the presence of a contaminant/solute?

Why does it decrease the surface tension? Also, what else, possibly a mechanical device would create the desired effect. Additionally, what other solutions would significantly decrease the surface tension of water?

How can I do this? Maybe some sort of oscillator? What would you recommend?

Haha... I acually intend(ed) to learn something from this project. From my experimentation, I have found that as I increase the resistance of the 180 ohm resistors, the AC current generated decreases (by about half). I don't get the mathematics behind why this happens, but conceptually it sort of makes sense. Here's how I think the circuit works: There are two transistors with bases controled by the two charging and discharging capacitors. These bases act as gates allowing the collector current to be amplified through the emitter. I'm guessing that the frequency of the current is generated by the charging and discharging of the capacitors. Thenceforth, I don't understand. I'm not sure exactly how these capacitors are charged to create the frequency. From my limited experience, it seems a capacitor, when connected to a power source, will only charge--not discharge and then recharge. How, specifically, is the frequency created? Maybe I should try using capacitors of different capacitances? Maybe this will alter the frequency? Can someone explain, mathematically, how the circuit works? As for the heat issue, I would think that the resistors would heat, but not too much. I mean, they chose high watt resistors to avoid the heat, right? I've more than doubled the power ratings, so I shouldn't expect any significant heating.