hermanntrude

please be extremely cautious with these experiments. They can often give unexpected results and there is often the danger of creating chlorine which can very badly damage lungs. Also if you use a car battery, be aware they can give nasty shocks and contain some vicious chemicals. Also be careful with the hydrogen if you make any. On its own it's dangerous enough but if it mixes with air or oxygen or chlorine etc etc it can be extremely explosive

I can see two possible ways of dealing with the transparency issue: 1) use a material for the container which is the same colour as one of the colours of the indicator 2) Use a different indicator which is colourless either at high or low pH

hmm so you're basically looking for a solid-state acid-base indicator that's non-toxic. perhaps this might help? many flowers and fruit contain substances which change colour in the presence/absence of acid. The trick would probably be in making it stay on the glass rather than dissolve into the juice.

theophrastus, please don't go digging up old threads unless there's something useful to say. The last post in this thread was nearly a year ago.

tell me more about what you plan to do with this chemical... I think i can see what you're getting at but i'm not totally sure

i was only being silly, by the way. it's all tongue-in-cheek.

you're trying to make potassium nitrate? why?

the trouble is that magnesium chloride and sodium sulfate are both soluble in water. What that means is that there is no reaction. all that happens is both your reactants will dissolve leaving you with four different ions floating about in solution. If one of the products were insoluble, a precipitate would be seen and u could isolate it.

do NOT try this at home. trinitrotoluene is TNT which of course is a dangerous explosive. Anyone who HAS tried this at home and would like to tell us all about it, please shut up.

a bomb would do it too :0)

I can help with a few of those questions: 1) To explain that mercury is a liquid requires the use of one of einstein's theories of relativity. I can't remember which one. It was a big mystery until relativity was introduced. Apparently relativity also explains the colour of gold. How exactly, i'm not sure. 2) not sure. good questions :0) If you tried a search on wikipedia I imagine you could probably find information on synthesis. I suspect it'd be different for some of the more strained cycloalkanes like cyclopropane and cyclobutane 3) [ce]KNO2[/ce] contains [ce]NO2-[/ce], which is the conjugate base of the weak acid [ce]HNO2[/ce]. The acid and base exist in equilibrium: [ce]HNO2 + H2O <=> H3O+ + NO2-[/ce] If you add [ce]NO2-[/ce] to the equilibrium, you are adding a product. According to le chatelier's principle, addition of a product of an equilibrium results in a shift to the left-hand-side of the equilibrium. This means an increase in the quantity of [ce]HNO2[/ce] and a decrease in the quantity of [ce]H3O+[/ce]. The only reason it doesn't result in a decrease in the quantity of [ce]NO2-[/ce] is that you ADDED some of it. Nevertheless, there will be less after the equilibrium is re-established than there was immediately after the addition. 4) Your question and your objection to the answer are the correct answer: Arsenic DOES have 5 valence electrons. Remember that the number of valence electrons is the number in the highest energy shell, ie the shell with the highest value of "n". In the case of arsenic, the highest shell is n=4. If you look up the electron configuration of As (or work it out for yourself), you will see that it ends in 4s2 4p3, which means there are 2s electrons and 3p electrons in the 4th shell, giving a total of 5 valence electrons. 5) i'm not sure of the semantics here but i've always felt that exothermic could technically be extended to include reactions which release energy in general, rather than specifically heat. Whether this is a belief shared by the rest of the scientific community, i'm not sure. Perhaps there is another word for our idea, but i don't know it. Perhaps exoergic? any further questions, give me a few days :0)

Bad theophrastus! Bad!

fererro rocher is a very expensive ball of nothing, with way too much packaging. When i buy chocolate i want most of the mass of the object i purchase to be chocolate.

no accusation intended. We just find it's wise to make it clear that safety is important at an early stage in this type of discussion. we have a few members who delight in being unsafe and telling the world about it as if it was a cool thing to do. Rob, your method could probably work but it'd be very hazardous and wouldn't give much HCl per day's work. Part of the difficulty is that depending on the voltage used and the concentration of the NaCl, some oxygen may also be given off with the chlorine

what you probably havent considered is the danger of melting sodium hydroxide. Sodium hydroxide is horribly caustic, causing very nasty burns to the skin. Melting it would mean you'd have liquid burning-stuff fizzing and bubbling under your nose at more than 300°C. The vapours would be very unpleasant. It'd also be much more reactive at such high temperatures. Just a drop of water might make it splatter everywhere. My advice is not to do this. But yes, in theory it could be done, with the appropriate apparatus, i think... although i'm not sure what would happen to your hydroxide ions.

You won't find an official supplier who will sell you the chemicals by name from a chemical catalogue, unless you are a bona fide institution (like me :0)). However, there are ways and means of getting hold of some chemicals if they are used in non-chemistry industries. For instance, hydrochloric acid can be purchased under the name "muriatic acid". Talk to some of our other members for advice on this type of thing, but be warned that we take safety very seriously here and if you appear to be attempting experiments which are unsafe for home, there could be trouble. read our hazmat policy before posting anything like that.

most of the reactions you want to do will work in a 10% solution. If you buy distilled, white vinegar (the cheap stuff) it's essentially just water and acetic acid. The pure liquid is a bit more hazardous and a lot more smelly.

perhaps it's because of the almost impenetrable layer of Al2O3 that forms on aluminum?

Copper(I)oxide and Cu2O are the same thing, no? Oh hang on... I'm thinking of CuCl, Copper(I)chloride. That's white. Yes you are right. However, if it's on the cathode it ought to be copper, since that's the reduction product, unless you do some fancy stuff

copper(I) oxide isn't maroon or red. I suspect the red build up is copper.

I'd like to answer this in detail but: a) I dont have much time and b) this seems a little bit like it might be a homework question and we only HELP with those, rather than actually answer them. Two suggestions: -use our search engine... this question has probably already been answered by our members -try googling "chemical bonding"

generally it's only metals that are on the (re)activity series. Having said that, the reactivity series is often described as being the exact opposite order of the increasing electrode potentials (electrochemical series). The difference is that in the electrochemical series, elements are listed as being oxidised/reduced even if the resulting compound(s) is(are) not ionic. The two interesting lines on the electrochemical series as far as you're concerned are: the reduction of silicon to silane (SiH4) and the oxidation of silicon to silica (SiO2) LINK

try biology

you can even get software which recognises your handwriting and turns it into typed text

I think it all depends on the actual disability. For instance, dyslexia doesn't imply stupidity. A person with dyslexia just has trouble with interpreting written symbols. It's not that they can't understand the question, they just can't physically read it very easily. Many jobs (and i admit, not all jobs) do not require the skill of reading something particularly quickly. Unfortunately, due to the method of examination, which is timed, often the qualification DOES require fast interpretation of written language. Now dyslexia is just one example, and many disabilities DO render a person unqualified to do a specific job, but i dont think the Universities should be in the business of deciding which disability makes you totally unemployable and which doesnt. Extra time in exams isn't an issue for me. Scribes aren't an issue either, as long as it's on record. That way any potential employer knows what skills the potential incumbent has or does not have and can select based on that.