Chemistry

This is question regarding sublimation. When we heat sublimants like ammonium chloride , Iodine etc it truns to vapor stage directly. Do they beomce vopour directly or the interphase ( liquid) is not noticable? What happens in the reverse ie when we condense vapors?

it says it in the title realy Where can i buy chemicals in the UK? not crap not working chemicals but things like pottasium,lithium etc...

What is external calibration? How can it be compared with standard addition?

Interesting... http://www.flixxy.com/alternative-fuels-research.htm

Hi, I'm doing some volunteer work at a high school over the summer and will be preparing labs for the AP chemistry students next year. I'm looking for ideas on fun, interesting and informative labs that a high school student can do in class. Time is not an issue if it is a very good lab. I'm particularly looking for labs involving fractional distillation and simple distillation, at least one of each. Thoughts are greatly appreciated. I'm not looking for a whole write-up or procedure, as that is part of the work I will be doing. Labs that are visually appealing and/or intellectually stimulating would be the best. Thank you.

It seems like there would be no reason for an electron to orbit an atom and much flimsier that they would orbit in different levels. I'm sure there is a good explanation, but if an atom had a +2 charge, why wouldn't it just lock onto the nucleus like a magnet wherever there was room, stacked onto other electrons if necessary?

Hi, excellent forum you have here! So, my question is one that has been on my mind for ages and I was hoping that someone could please put me out of my misery..... Is there such a liquid that stays cold even if it is heated? For example, say the liquid was contained in a beer can, completely sealed and then put in a hot atmosphere like an oven, is there a liquid that you know of that will stay cool? Thanks in advance and I look forward to your replies

Someone on Yahoo Answers who claims (s)he has a physics background wrote that solidity is only an illusion, because there are so many atoms, and we would see that atoms are mostly space at the sub-nanometric scale. (S)he also wrote that there is 'no solid, no liquid and no gas. There are only atoms and atoms are mostly empty space with nucleus of protons and neutrons and electron clouds.' It's just that I thought that the bonds between atoms/molecules determine whether they are solids, liquids, or gases: independent atoms/molecules with no bonds for gases, Van der Waals or weaker interactions to keep atoms/molecules together for liquids, and stronger, cohesive bonds …

I was pouring myself some pop the other day in a small styrofoam glass filled with ice. Less than 30 sec. later, after guzzleing down the drink, I noticed that the size of the ice cubes in the glass had decreased dramatically. Why did the ice melt so quickly? Could the dramatic melting of the ice have to do with the fizz of the pop (CO2) or does it have to do with the sodium that is in the pop?

On average, is the electron in a 4s orbital farther out than the 3d one? Or is it the other way around? Do electrons in the 5s shell tend to be farther out than the ones in the 4f? And also, can you explain how the electron's energy in each orbital fits in to this. Thanks in advance.

I don’t if I should have posted this here of in a physics one so I will try here first. Going from the periodic table it seems as if you can have more and more in regards to a nucleus and the surrounding shells. Is there a limit to this? Could you have an atom or element with say 2000 protons, or 2500 electrons? It seems going back or getting smaller there is a limit with hydrogen maybe? I just don’t know the upper bounds of it anyone has tried to find out actually. I cant really find anything about this on the net.

Hi everyone, I hope you are all well. I have an idea for my final year chemistry project involving the surface modification of motorcycle helmet visor material; I understand that it is a polycarbonate of sorts, but how could I investigate what the repeat unit structure is? I need to find out before I start on the chemical modification I guess an infra-red spectrum could yeild some information, but are there any other methods? What about some way to break down the polymer to its monomers, and then investigate that? Matt

hello, i was doing some experiments and managed to make some nitric acid and i don't know the percent. is there an easy way to determine the percent???also, the sulfuric acid i used to make it, i also had no idea what the percent was. if any body knows a highly effective way to determine the percent of the acid it would be great. thanks!!!

Hi, I was wondering if anyone knows how you would go about creating zinc sulfide? I presume adding zinc to copper sulphate will result in zinc sulphate and i'm not all that crazy about smashing up a CRT screen for safety reasons Any advice?

Ok I have a question......here is what I am trying to do.....have a image put onto a surface but it will be unseen.....i then spray water or something onto the surface and make the image appear. How can this be done????

When we put some glycerene on potasium permoganete wrapped in filter paper it catches fire. What is the reaction going on. Can we do similar experiments with other chemicals for example white phospprous? Thanks Murulidhara

I work in a microbiology/genetics lab at my university. This morning, I was in the middle of an experiment, when I heard shouts from the other side of the lab. "Get out everyone, there's been a chemical spill in the building, everyone has to get out now." So I quickly grab my laptop, and my labmates and I run out of the lab. While walking down the stairs, a group of firefighters, garbed in full gear, complete with oxygen tanks, fire-axes and crowbars rush past us up the stairs. I'm sort of scared now, because I'm thinking if they need O2 tanks to avoid breathing in vapours, then it must be pretty serious. Also, I was keenly aware that they weren't providing b…

What is white gold? What is its composition? where it is used? Murulidhara

can anyone give me a answer on what is the complete equation of: 1)Na2CO3(s)+H2O(l)-->? and how to explain these equations(procedure run by using titration technique), is that happen impromptu?The CO2 dissolve in the aqueous? Na2CO3(s)+HCl(aq)+H2O(l)-->NaHCO3(aq)+NaCl(aq)+H2O(l) (1) NaHCO3(aq)+HCl(aq)+H2O(l)-->NaCl(aq)+H2CO3(aq)+H2O(l) (2) NaCl(aq)+H2CO3(aq)+H2O(l)-->NaCl(aq)+CO3(aq)+2H2O(l) (3) *Na2CO3(aq)+2HCl(aq)+H2O(l)-->2NaCl(aq)+CO2(aq)+H2O(l) (4) is that excess of HCl titrated into the Na2CO3 when over the equilibrium point cause the second equation happen or it(2) will just happen if HCl titrated in…

So I have a mixture of NaCL and 2NaHCO3, table salt and sodium bicarbonate. I need two methods of finding the proportionality of the two in this mixture, and I am given the use of anything in the lab. My first method involves weighing the mixture, weighing some HCl, adding the HCl, stirring for a few minutes, and weighing the result. I should be able to find the weight of sodium bicarbonate in the mixture by using the weight lost by changing to gas and the chemical equation: 2NaHCO3 + HCl = NaCL + H2O + CO2 If this first method looks good, then great. But I am completely lost on the second method. I looked at the thermal decomposition of 2NaHCO3 and found that it…

For the transition metal element Cr why are there 5 electrons filling the 3d orbital and only 1 electron filling the 4s orbital? I initially think that there should be 4e in 3d and 2e in 4s Why is my way of electron configuration less stable than the one in the question? please help thanks

What is cold flame. In some exhibitions i have seen flames which doesnt burn. How is it formed? What is the principle? Thanks

Hi all, I wasn't sure if this post should go in the chemistry section or in the biology section so I decided to post it in both. Sorry if this is frowned upon. If so, maybe there should be a general science section Anyway, I have had a lot of problems with roots growing into my sewage system at my place and backing my toilet up. The plummer told me that I should put some copper sulphite gems into the toilet as it would help kill the roots. I specifically asked him if it was definitely copper sulphite and not sulphate (as I can appreciate he is most likely not a chemist) and he said yes. He told me that I could get it from most garden centres. So I went to the garden …

Hi everyone, sorry for keep posting on here to ask questions, right now though if i come accross something i don't understand this is my best resource - i hope you all don't mind. If you have a formula, say CaCO3 (just for example, my question isn't specific to this formula, it's a more hypothetical one) how can you tell how these elements have bonded? Is it covalent or ionic? Also, I've seen H2O written with (l) after it denoting it is in liquid form. But then in the same formula I've seen other elements written with the (aq) to denote disolved in water. If something is written with the (aq) after it, but H2O is not part of the formula, does it mean that the…

I have scanned the web, read chemistry books, and so forth, and I cannot figure out these Chemistry questions for the life of me, although they are probably very simple to answer for others. Unfortunately, I took Biology in college and never had a chance to ask these to a professor. Also, I think I have a mental block when it comes to anything involving particles. 1) Why can't Boron accept 5 other electrons in covalent bonding, as Carbon accepts 4, thereby making it an even better candidate than Carbon for the basis of complex molecules and living matter? 2) Why do heavier elements have more trouble forming complex bonds? Silicon has almost the exact same vale…