hermanntrude

aldrich has most glassware in it's glassware catalogue. If you find anything which looks like it was made by a glassblower with hiccups, it's probably a soxhlet extractor

both my examples were of metals as elements in the gas phase

gases can certainly exist as gases. Google manganese dioxide thermite Merged post follows: Consecutive posts mergedalso don't fluorescent lights contain mercury? is that metallic mercury? not sure...

not sure if the salt makes a lot of difference

thanks for the info IA. Do you think it's possible to make two substances which are compartable (have the same chain length), given that my lab is fairly old and cheap?

I was talking with our good friend Insane_alien this morning in IRC, and he mentioned to me the fact he synthesised some disilane in the lab. I myself have made silane from magnesium, silica and HCl before, and I was thinking how a good demonstration could be made out of using a hydrocarbon and its silicon-based analogue, showing that the hydrocarbon requires additional heat to reach the activation energy for combustion but silane or whichever silicon-based analogue I choose doesn't. the trouble is ideally i'd like to use analogues, ie methane and silane or ethane and disilane. It's not entirely neccessary but It'd add to the level of comparability. any suggestions on how to make my silane(s) or what to use for my hydrocarbon would be appreciated, or any suggestions on the lab in general...

sometimes a paste helps. Perhaps a mixture of vinegar and flour... you could smear it on, leave it for a while and then scrape it off. I've heard of people cleaning copper and silver this way

your calculations are perfect in every respect except for your conversion of 30ml into L. 30mL is 0.03L, not 0.3. you are correct in your understanding of "6N" Merged post follows: Consecutive posts mergedi make it a bit more than 15g. be careful when you do this. the fizzing will mean a lot of HCl fumes are released, and you have a fairly concentrated solution. Do this ina very well ventilated area, protective clothing, safety glasses and stand well back.

the only thing I know for sure that lead carbonate is soluble in is nitric acid. I doubt you want to clean windows with that, though :0(

what you need to do is this: 1) find out how many moles of HCl you have 2) use the chemical equation for the neutralisation to determine how many moles of bicarb you need 3) calculate what mass of bicarb that equates to step 1 I cannot help you with unless you know the concentration of your HCl. If you can find that out, I (and many others on the site can help you with this calculation. it's simple). step 2 I can help you with. the equation is this: [ce] HCl + NaHCO3 --> NaCl + H2O + CO2[/ce] What this equation tells us is that one mole of HCl reacts with one mole of bicarb. In other words, however many moles of HCl you have, you need the same quantity of bicarb. step 3 will need another calculation. Whatever number of moles of bicarb you require, multiply by the molar mass of bicarb (84 g/mol). This is your answer in grams.

I'd guess it could be lead oxide or sulfide or something. I could be wrong too.

probably not. don't mess with that stuff. Also, IUPAC names are the new thing. try them. people might know what you're talking about more often.

I'm planning to make this into a demo... currently my idea is to first start with the usual platinum loop and bunsen burner and then introduce the ethanolic solutions so people can see it better, talk a little bit about the reasons for the emissions and then hopefully demonstrate it using a spectrophotometer made from a CD, a cardboard tube and a webcam.

or perhaps he's required to label it for beaurocratice purposes.

dissolve a small amount in as little water as possible, add a bunch of alcohol (ethanol) till the solution is flammable but still dissolving the unknown sample, then set light to a small quantity of it. If the flame is bright orange, you have sodium hydroxide, if it's blue or lilac, it's potassium. Merged post follows: Consecutive posts mergedor you could titrate a small amount against a strong acid (HCl perhaps) and do the math to see how many moles were in your sample, then you'll be able to calculate it's molar mass.

there's a journal called macromolecules. They have some VERY good authors <polishes nails on lapels>

nice method. Of course, KBr is dirt cheap anyway :0)

OK so today I tried a new demo and i'm very excited. Before I start I should remind everyone that this cannot be attempted outside of a proper chemistry laboratory. Bromine is extremely hazardous and hard to safely dispose of and handle and the same is true of potassium. Anyway, what I did was this: I took a long piece of metal (steel, i think), and bent the end downwards by 90°, so that the end part was just long enough to reach the bottom of a large beaker. To the end I attached a piece of copper wire. Into the large beaker I placed a small beaker with enough bromine in it to cover the bottom. To the top of the bent part of the metal stick I attached a DVD so that when the stick was fully inserted into the beaker, the DVD would cover the opening at the top of the beaker. I then attached a very small (perhaps 2-3mm diameter) piece of potassium metal (washed in hexane and dried in air) to the wire at the tip of the metal stick. I then placed an explosion guard over the front of the beaker and lowered the sash of the fume hood as far as possible. Then I lowered the potassium into the bromine. A small explosion ensued and copious quantities of white smoke floated gently away into the fume hood. it was awesome. Video to follow at a later date.

please spend some time checking the MSDS for the reactants and products of these reactions before attempting them, and make sure to pay special attention to ventilation. ammonia is very unpleasant without adequate ventilation, and sodium hydroxide is downright dangerous in the hands of the unprepared, as is ammonium nitrate

don't bump, please. No-one wants to answer your thread.

i'm sorry you got negative rep for that... it shouldn't be that way. No scientist should ever be afraid to ask a question. Having said that, isn't it obvious chemistry still needs a lot of work? After all, a bacterium, or even a virus can synthesise DNA in giant quantities to a very precise order of the base pairs, but to do that in a lab would be almost impossible. There's many other examples of course

the alcohol is ethanol usually.

don't melt any real tin tin soldiers... they'd probably be more valuable in their soldier form!

well done, melvin. You've made sulfuric acid. How pure it is another question of course. Think twice before you use it for anything you'd normally use sulfuric acid for... any potential impurities might cause unexpected reactions. I'd also like to point out once again that your methods weren't really suitable for home chemistry... boiling acids are extremely dangerous. Please don't try this again without a fume hood, lab coat, goggles, acid-spill kit and a fire extinguisher handy.

remember the definition of pH is [math]-log[H^+][/math], where [H+] is the concentration of H+ ions in solution (bear in mind that most textbooks beyond a certain level will actually refer to the concentration of H3O+ instead of H+, since this is more technically correct). If you think of that, it's no surprise that a negative pH can exist. Any concentration greater than 1mol/L will give a log which is positive and therefore a negative log (and pH) which is also negative.