Applied Chemistry

Hello everybody, Can you science fellows help me to find the most commons chemicals for PCB enchants (metal dissolution). I read about aqua regia, FeCl3... but if you know something else please let me know. Thank you,

I want to melt a very small quantity of gold so I'm looking to make a.. well, call it a microcrucible. I want to avoid metal because I don't want the gold to bind to it. I have a graphite crucible, but it's much too large. I have some high-purity 0.5" carbon rod, and I'm wondering how it could be made to work. Say, if I take a one-inch length and make a well in it. So, my questions: How would the straight carbon react to open flame? Is there a way to graphitise carbon rod at home? Maybe I could use it to make a tiny induction furnace? Anyone have any (constructive <grin>) comments or suggestions? Thanks!

People, Is this too easy- if I take salicylic acid powder, then add NaOH to make sodium salicylate? The stuff has shot up in price and if I can react this this way, would be way cheaper. Thanks!

Why Bohr's theory cannot explain the atomic spectra of He,Li, etc, i.e., systems with more than one electrons?

Why does the energy of a system decrease when two charged particles attract each other?

Hello, I am an artist and I use silver leaf in the course of my work. The leaf is approx .2 microns thick and I apply it to glass. Previously I have used a combination of Cupric Nitrate and Ammonium Chloride to etch the leaf in order to get a variety of desireable effects - anywhere from a light grey to deep black etch. I have also used Barium to acheive a beautiful red/brown effect. However, I am now living in a country where it is proving difficult to source these materials. Are there any other substances that i could use that are not too toxic and might cause a similar reaction in the silver leaf ? Thank-you

Hello everybody! We are two students in a swiss high school, and we just began a chemistry project: we are working on the production of carbon nanotubes by magnetron dc sputtering method. We have been working for some months, but we still have lots of problem: the depositions are scant and we actually don't know if they are nanotubes. Our deposition on silicon platelets should show nanotubes geometry (that's the common method to identify them), but we still haven't found any of them. We use a pure graphite target. The working parameters are: Pression: 2-3 x 10^-1 Torr ΔV: 500 V Current: 40-60 mA I'm not going to post our whole work, that's only to briefly ex…

People, I have Class S NIST weights, but I dont understand what is meant by "tolerance" when calibrating a Mettler. Say, I grab a 100g weight, zero the scale, place it on the pan, and get a weight - say 99.9965g. That is pretty good to me, but when a manual says "calibrate to NIST tolerance for class s ", what do they mean? Sjhouldnt that imply a min /max tolerance? Where then do you find this tolerance? Thanks

Hi, I'm planning on making some concentrated ammonia solution and I'm a little confused as to the math. I plan on heating some store bought ammonia, which I already determined is 10%, and bubbling the gas through water. What I'm confused about is how to convert from w/v since the density of water changes depending on how much ammonia is dissolved. Do I need to know the density of 10% and 35% (that's saturated, right?) to figure this out? Anyways, any help is appreciated. Edit: I think some of the trouble I'm having is from wikipedia's article on ammonium hydroxide. It says "At 15.5556 °C, the density of a saturated solution is 0.88 g/mL and contain 35% ammoni…

Hi. I may have asked this looong time ago before, but, trying again... What liquid chemical preparation would be electrically conductive after drying ? Other than commercial silver inks or powdered graphite in a binder. Feel like binders insulate the conductive 'dust' particles, would prefer something different. Elastomeric contacts as in a remote control are coated with a compound that rubs off with time. A soft pencil deposits a layer of conductive graphite on them as to extend its life somewhat, but am after something more durable. Suggestions, please ?

Hi everybody! I need your help. Hw can i reduce bromate problem in the drinking water? As you know when we ozonate still water and if our raw water has bromine finally we will face bromate problem. I searched on the internet and found some methods about it. but most of them are not free. Speacially i`m interested in ferric sulfate method. Who knows about it? And you can also tell me other method. Thanks in advance!

I need ferric nitrate in order to etch silver, I was told that I could make it by combining nitric acid and iron filings. Now from what I've read, this appears to be true, but what I don't know, is what proportions and conditions I need to create ferric nitrate.Does anybody know what those are?

Years ago I use to order in from Fed Log MD 20/20 lenses about 2-3 inch dia. The lens was blue onto that of cobalt furnace glass and very brittle also. The glass was a remote viewer for finding things real creepy like black widow spiders, the lens would totaly suppress the back ground blue, but when there was any trace element of thrediidae it would pass it through the glass a phospher white. What would the glass be composed of? What would the intitals represent? The 20-20 would be a percentage of a mix, what chemicals? So just how would I go about making this excitation filter to find spiders. I no longer have access to Fed Log and it is a highly secretive source and t…

So i spilled HCl on my brown chino pants, not while wearing them. They are still intact without visible corrosion or holes, fabric is intact. Sad part is that the parts of the pants the acid soaked is now permantly discoloured, with light red stains. What does HCl do to the brown pigment to make it red? Chemical reaction with lightabsorbing aromatic pigments that changes its structure and therefore absorbtion spectrum? This might sound really minor, but i really liked those pants, they fit me like a glove. When it happened, i soaked them ASAP in a bucket of cold water, then washed the pants in the washing machine. The stains are still there, unchanged. The dye of …

Hi Everyone, I'm new to this forum. I was reading a thread in your forum from last year that dealt with cleaning silverware with ammonia. The discussion got rather heated at times. I didn't understand all of it, but I don't believe any of the thread addressed my problem. I just came back from the silversmith who charged me $20 to remove a small area of extensive corrosion caused by salt in a sterling silver salt cellar. Silver polish had been ineffective at removing the corrosion. I suspect that I got ripped off and believe that if I only knew the proper "do it yourself method", I could probably take care of this prolem in the future for mere pennies, some time,…

This is actually two questions: I have a nickel crucible in which some bismuth was melted, plus other contaminants. (Specifically, as part of a traditional Marshmallow Peep torture party, a peep was eviscerated, filled with molten bismuth, and the remains put back in the crucible. Fun.) The question is, what's the best way to clean out the detritus (bismuth oxide, random schmutz) and restore the crucible to near-pristine state? To what reagents is it particularly resistant but that might tackle the dregs? On the other end of the spectrum, I'm trying to remove the metal jacket from some large dry cells. (I'm trying to reclaim the encircling carbon relative intact.) T…

Hi! I am searching for all carcinogenic substances for my lab teacher because she has an old version of it. Can anyone help me?

How can you calculate how fast oxygen levels will fall and carbon dioxide will rise per person in a sealed room of a certain volume, and what levels of each will likely cause death?

I grow bismuth crystals to make sculpture and jewelry. Every time I melt, I lose a bit to oxygen on the surface. I've collected enough slag to prompt the question. Can I reduce this efficiently to offset my $22 per lb for the new stuff? Thanks for considering my problem. Ernie

Hi. Ethanol mixes with gasoline, Water mixes with ethanol; What happens if ethanol with some water dissolved in it is mixed with gasoline ? Is there separation ? What are the components that separate ? Is there a ratio when it does not separate ? What if it is methanol ?

I am in search of naturally occuring sulfer in concentration, or an economical means of isolation/purification. at present i am experimenting with pyrites. i require cheap purified sulfur for producing my own black powder. the powder is not to act as an initiator, it is for muzzleloaders and hobby cannons.

Hello, I need help to make a citric acid solution in water taste-free or at least not sour. I understand that it is the Oxonium ions formed in aqueous solution that provides the sour taste. I wonder if there is any substance that causes the sour taste to cease? The fluid should be drinkable ie I should be able to drink it without it being harmful in any way.

Hi Which household chemicals do a decent job in rust removal, rust dissolving ? Seen too many 'recipes' that make not much sense, others perhaps do. What to expect spraying : -lemon juice, -vinegar 5%, -diluted baking powder, -diluted baking soda, -diluted borax (sodium tetraborate), -diluted washing soda (sodium carbonate) -oven cleaner -bleach -'liquid plumber' -acetone -kerosene -transmission fluid - and whatever else you can name. Or combinations of these. And what about rust neutralyzing or prevention ? -Caustic soda (sodium hydroxide) solution, What else ?

What would happen if you were to boil lets say a 1 liter solution of pure ammonia? Would it just become ammonia gas, or would the hydrogen bonds eventually break yielding gaseous hydrogen and nitrogen. (I'm trying to find a reltatively cheap way to obtain pure hydrogen gas without utilizing electrohydrolysis).

People, (oops, I meant to add a "2" after the Na in title) Say one has a 50lb bag of sodium hydroxide pellets, saved for 5 years. Then, say it turns into a solid rock. Then , say one smashed the rock into bits and dissolved the whole mass. In your opinions, how much of the NaOH would have absorbed carbonates from the atmosphere ? When that happens, is it part of the NaOH converting to carbonates, or is it the NaOH is still there and just that the carbonates are adhering/adsorbing onto the NaOH pellet's surface? Thanks! Oh- if it "converts", is it likely that the entire NaOH can convert over to be fully Na2CO3?