hermanntrude

cautiously smell it (waft a small amount toward your nose with your hand. It's probably chlorine. A concentrated salt solution will electrolyse to form chlorine and hydrogen. be careful with chlorine it's highly toxic and quite unpleasant. it's also yellow. The vinegar probably didnt do much at all. be careful messing around with chemistry. it seems that you're not very experienced and that can be extremely dangerous.

well done. that's the reaction they're expecting you to work with

the phrase free radical covers a wide range of substances. Technically nitrogen monoxide is a free radical but it's stable at room temperatures. other free radicals are so reactive it's hard to know they ever existed because they react so fast. Ideally you need to find out what type of free radical you're investigating, because if you put one type in you'll get one result and if you put another you'll get another.

not really, no.if it was you'd expect it to form a positive and a negative ion. You might be able to get copper 1- ions if you put it with cesium (gold does that), but i'd hardly say it's amphoteric. it might have amphoteric oxides though...

Captain, many exams and other tests require students to memorise some "solubility rules" so that they can predict the outcomes of precipitation reactions. Your method, while better for an actual experiment, is unhelpful in these situations. Please try to remember the people who ask homework questions are not dedicated scientists who want to do things the absolute best way. Often they are hard-working students who have to learn an awful lot in a short space of time. Complicating the issue often doesn't help, even if it is more precise.

there are theoretical ways to calculate the solubility of salts, but i expect these tables were made on a trial-and-error basis like you described. Your last question makes no sense... magnesium isn't ever said to be "insoluble with hydroxide". All you can really say is that magnesium hydroxide isn't soluble. I don't see why you think that we can "assume hydroxide is insoluble with magnesium because hydroxide is insoluble" no such assumption has ever been written down in a textbook. I think perhaps your problem is that you're searching for hidden meaning in the solubility rules. At this stage of learning, you can't really do anything except accept that the rules are what they are. There's no way for you to empirically derive them.

there is an empty one before the adduct is formed.

I think you're right. Really, it's an analogue of a salt. It's what's left AFTER the acid-base reaction is finished. However, pretty much anything can undergo an acid-base reaction if hit with a strong enough acid or base...

however, the question explicitly states that ONLY the COOH group reacts with the NaOH at the conditions of the titration.

I'm not sure if atheist's method is more precise but I suspect that your question is expecting you to assume the water molecules occupy no volume in themselves (they are point masses). This is a common assumption in the kinetic theory of gases, although it's obviously not true it often gives a very respectable answer. I'm not actually sure how to go about the math but i suspect that assumption is your first step.

I'd imagine that the recipes originally would have used very strong vodka rather than pure alcohol. It's very hard to make pure alcohol, even when it isn't illegal.

you need to look at the equation for the reaction: [ce]2NaHCO3 + H2SO4 -> 2H2O + 2CO2 + Na2SO4[/ce] To calculate how much [ce]NaHCO3[/ce] is required, simply take the number of moles of [ce]H2SO4[/ce] (1) and multiply by "wanted over given"... what I mean by that is the stoichiometric conversion factor. You can construct the conversion factor from the stoichiometric coefficients in the equation. In this case the stoichiometric coefficient for [ce]NaHCO3[/ce] is 2, and the stoichiometric coefficient for [ce]H2SO4[/ce] is 1. In other words the math requires is like this: 1 mole [ce]H2SO4[/ce] x [math]\frac{2 moles NaHCO3}{1 mole H2SO4}[/math] = 2 moles [ce]NaHCO3[/ce]

I have a set of emmission tubes (filled with various gases through which you can pass a high voltage), and one of them is air. it's a blue/white colour just like lightning

white phosphorus DOES ignite in air if it's pure enough. The reaction is exothermic even if there are no flames. this heats up the sample until eventually it goes crazy, spraying molten phosphorus everywhere. Now I don't expect there's enough WP in my RP to make that happen, but I'm surely not going to go leaving it in the sun to find out. Not at a public college.

I'd be extremely surprised if you get anything other than hydrogen, oxygen and perhaps a bit of gunk

nice. I didn't realise it'd be so easy to extract

where did you get a supply of pure acetaminophen?

so what could make up my 10% impurities then? other allotropes? black or violet perhaps?

are u one of the people in the video?

The sample's original purity was only 90%, so I will have to assume that the impurity is white phosphorus and perhaps other allotropes and also that there might be some phosphine present. I will proceed on that basis. thanks

thanks for the advice, dr syntax, but i'm not inexperienced. The stuff I have is red phosphorus, perhaps contaminated with another allotrope. I've looked at the MSDS sheets (generally better than anecdotal scare stories) and they tell me that i'm safe if i dont inhale more than 50-100mg of pure white phosphorus. Also the garlic reference is to the smell of people's breath when they have inhaled or otherwise consumed too much white phosphorus... apparently it's one of the many symptoms of poisoning, along with vomiting, nausea and abdominal pain. Red phosphorus, btw is considered non-toxic by inhalation. what concerns me is that perhaps my red phosphorus contains some white phosphorus, since it smells so bad.. or perhaps red phosphorus has a smell? Merged post follows: Consecutive posts mergedcertain MSDS sheets seem to be indicating that it's the combustion of P4 which results in the garlicky odor... perhaps it's the smell of the combustion products, P2O5 and others?

I have been planning an experiment using some red phosphorus, and today decided to have a closer look at my extremely old sample. It's in a can like a paint can, which worries me because the MSDS states it can ignite due to friction, and the can stays shut simply by friction and every time I open it i have to pry it open. Not only that, but it stinks like sulfur. Why would it do that?

technically, hydrogen is a metal. An alkali metal. The whole thing is bit fuzzy, hey?

it all depends on how you define a metal. For most people a metal is simply any element to the left of the staircase line. Certainly the high attractions between the atoms and the lustrousness and greyish (or goldish) colour are all characteristics, but the definition is simply that it's to the left of that line.... of ourse the reason for that line lies in the fact that things to the right are electronegative and the things to left are electropositive, but that's a bit of a generalisation too...

I have one of those demo sets for showing atomic emission. One of the tubes contains mercury which you can see is liquid before you turn on the current but it vaporises when the current is on... I always assumed fluorescent lamps worked the same