hermanntrude

most analytical chemistry is applied, anyway

eat horse manure? punch people? make bombs? shoplift? wear red with orange? there are lots of things you shouldnt do while innoculating a petri dish

the good thing about having bth hydrogen and oxygen is that you can fill balloons with both, and another with a mixture. the oxygen balloon won't do much, the hydrogen balloon will explode and the mixture balloon will blow up noisily and violently

get stronger hydrogen peroxide, or even a lecture bottle of oxygen. commercial oxygen generators use sodium chlorate and iron powder... when ignited they produce oxygen at a steady rate... perhaps you could use that too. sodium metal tends to form oxides and other things in air which prevents it from reacting when you want it to. to help with that, drop a drip of water onto it to get things going. another good demonstration is the combustion of sodium in chlorine, which again, often requires a drip of water to start it, but goes like a bat out of hell when it goes.

moved to homework help. the information big314mp gave you should be enough. If you can't see how, check your textbook, ask your instructor, or PM me

liquid nitrogen is sold under pressure and stored in pressurised containers. the reason of course is that if you leave a flask of it at room temperature and pressure, it will boil off in a few hours. But yes, certainly you can pour it into that tray and it will freeze the oil before it boils off

moved to homework help. Please don't just copy out the question. Try to tell us which part is giving you such difficulty, and discuss what you DO know, to help people give you hints and guide you in the right direction. Judging by your original post, i'd suggest your first port of call should be the wikipedia, followed by reading some of the references cited there

what is your desired end-product? a secondary amine? a tertiary amine? a quaternary amine? or perhaps even an immine?

keep it till it stops doing what you want it to do, then buy some more.

get an aldrich catalogue. they're free.

i'm not sure if it's sensible to speak of one half-reaction being coupled with it's own reverse reaction. You could, of course, speak of the reaction with the reduction/oxidation of water, which does happen in significant quantities with the more reactive metals... I don't honestly know if there is a reaction with water for the less reactive metals and there just isn't very much of it (the case where the equilibrium constant is very small), or whether it just doesn't happen because the reaction is non-spontaneous due to the cell potential being negative. I think it also depends on the specfic half-cell

I used to get headaches any time I used chloroform for running columns

what about pyrites? If you head out to wales there's a fair quantity of iron pyrites in the quartz bearing rocks. perhaps you could get sulphur from that?

This is how I go about it: I go to wikipedia, read the article, assume it's true, check the references stated by the author of the article and see if they seem viable. Often I also seek out another source of information to see if it corroborates the story I read on wikipedia. In general I find that wikipedia is an excellent source for scientific information PROVIDED it isn't a field which is big in politics recently. For instance, I would trust it if i was looking up the atomic radius of argon, but i would be much more skeptical if i was looking up the estimated quantity of crude oil in alaskan oil-fields. What I think teachers often say is "never use wikipedia as a reference" In many cases what they mean is "never cite wikipedia as your reference... instead, cite the reference cited in the article you read in the first place" what it is often mis-read as (by teachers as well as pupils) is "wikipedia is bad and full of lies, do not use it!" which of course sparks a lot of debate

mEtEr, not mOtOr

welcome to the forum, little miss clever. If you are a proper nerd, have aspberger's syndrome, OCD or are just really pedantic, you'll probably have a ball here.

wittig reagents generally react faster with aldehydes than with ketones IIRC edit: it might even be that wittigs don't react with ketones at all... i'd have to look it up... i think they do, but they'd react preferentially with an aldehyde

It's not nice to play with in any country but which ones have that law?

i'm not really sure how your question differs from the first one. if you want to show appreciation for anyone's responses, click the scales at the top right of someone's post

the reason that the canned chemicals cause freezing is that the liquid inside the can is usually a gas at room temperature. As soon as the liquid comes out (and lands on your electronics) it starts to evaporate, very very fast. Evaporation requires energy, and that energy comes from the liquid's surroundings (to some extent, this is your electronics), which cools the surroundings down. In other words it's the process of evaporation which is endothermic, not the fluid itself. I'm not sure I can think of a method by which you could do the opposite conveniently...

Personally, i feel that anyone with the name "amateurbombtech" should be responded to VERY cautiously, especially when asking how they can get potassium nitrate for cash (ie in an un-trace-able way)

one thing which people don't learn until late (too late, in my opinion) in chemistry courses, is that ALL reactions are equilibria. When we write the one-way arrow to indicate a one-way reaction, what it REALLY indicates is that the reactions equilibrium constant is so large that there are no reactants to speak of left at the end. However, there is always a little bit of the reactants left, and often in a reaction which doesn't appear to "go", the only reason is that the equilibrium constant is so small that there are only tiny quantities of reactant at any one time. Reactions which don't appear to work can also be non-spontaneous or incredibly slow. If you're doing a chemistry course you'll come across these topics later on in your curriculum.

half-reactions cannot occur on their own. the reason for this is that electrons aren't fond of being alone. What you are missing is that there is a half-reaction for water too, so if zinc is in water, the zinc has a small tendency to lose two electrons and the water can pick them up and undergo its own half-reaction: reduction: [ce]2H2O + 2e- -> H2 + 2OH-[/ce] E°=-0.828V oxidation: [ce]Zn -> Zn^2+ + 2e-[/ce] E°=+0.763V total: [ce]Zn + 2H2O -> Zn^2+ + H2 + 2OH-[/ce] E°cell = -0.065V This reaction is not spontaneous, however, since the sum of the electrode potentials for the two half reactions is negative, so we don't see a reaction. The reaction can occur, but a little bit of energy needs to be applied before it will. If we chose a metal which is slightly less attached to its electrons, however, we could see that it can and does react with water: reduction: [ce]2H2O + 2e- -> H2 + 2OH-[/ce] E°=-0.828V oxidation: [ce]Mg -> Mg^2+ + 2e-[/ce] E°=+2.356V total: [ce]Mg + 2H2O -> Mg^2+ + H2 + 2OH-[/ce] E°cell = +1.528V Since the sum of the electrode potentials for these half reactions is positive, it means that magnesium will indeed react with water, separating it into hydrogen gas and hydroxide ions, which will essentially cause magnesium hydroxide to form. note that these values are only true for 1M solutions at 25°C using standard electrodes. As you study electrochemistry further you will find there are equations for predicting non-standard situations

probably just because it's digital video under non-sunlight

very true. Good reasoning there, jdurg.