Chemistry

Does anyone know a good website with tons of molecular geometry and VSEPR diagrams? Are there any books that contain many of these diagrams? Perhaps with descriptions of the experimentally found angles and more?

Hi everyone, I'm just curious, is there a rule or pattern for calculating the charge of a polyatomic or radical ion such as sulfate and cyanide? For example, carbonate has a charge of 2-, and phosphite has a charge of 3-. How can you work out their charges without "memorising" them off a sheet? Thanks

Does anyone have a good scematic of this peice of apparatus? It seems quite unusual (not as common as the faithfull rotary evaporator) and I can't find a good diagram or picture. The one on wikipedia isnt very clear, and other google search results show nothing really usefull. Matt

We have been having issues storing 200L-600L of our stock NaOH solutions. We originally had them in (VLDPE) very low density polyethylene bags with silicone tubing built into them. We started seeing white flocs and determined that it was from the tubing manifolds. Now we are currently making 0.1M, 0.5M and 1.0M lots in increments of 300L dispensed into 50L (EVA) ethylene vinyl acetate bags with C-flex tubing and we have started to see the same issues. I am wondering if anyone has any imput on long term storage of NaOH's that doesn't include keeping it in stainless steel tanks???

http://news.bbc.co.uk/2/hi/science/nature/6584229.stm

Hi all, I'm fairly new to the forums and wanted to say g'day. Also fairly new to chemistry (1st year environmental science student) and am about to fail my mid semester exam terribly I think . Can anybody tell me, when given a strong acid (or base), how does one work out the conjugate weak base (or acid)? Also if given the weak acid (or base) can one work out the strong base (or acid)? Is there an easy way of telling what it might be? Any little techniques to work it out? Thanks.

Hi, i have a few questions. These appeared in an A'level paper and since i am to prepare for my next month exams, i am doing some past papers and i have a few troulbles doing these questions. Any help will be appreciated by who so ever writes in!. 1.Which reagent, when mixed and heated with ammonium sulphate, liberate ammonia? A. aqueous bromine B. dilute Hydrochloric acid C. limewater D. acidified potassium dichromate(VI). Well i thought it was B, dilute hydrochloric acid but the mark schemes say that lime water will release ammonia. How come? Another question is the one concerning esters with its displayed forumla given but i could not att…

You know those freezer pop things? The ones that are basically plastic tubes of liquid sugar that you stick in your freezer, cut apart, and eat? Mine are behaving strangely I'll put 10-15 of them in the freezer at a time. I don't lay them flat; Instead I bunch them together and stick them whereever there is a spot. Theoretically, they'd all get cold enough to freeze, right? No.. Not quite. Sometimes, no matter how long I leave them in the freezer, the ones in the middle will remain liquid. I dismissed it as them not getting air hitting them, so they won't freeze. Surface area and all that stuff. I hadn't paid much attention to those unfrozen pops. I…

Here is an interesting question. Suppose you have to prepare a half liter of 10^5 ppm solution of Iron in 15% HCl using Ferric chloride hexahydrate. So (10^5 mg/L Fe) x (0.5L/1) x (1g/1000mg) x (~270g FeCl3*6H2O/~55g Fe) = ~ 245g of FeCl3*6H20. Now my question is. How much concentrated HCl (lets say 35%) should I be adding to get a 15% solution ... taking into consideration the hexahydrate is going to be taking up space?? I have an idea myself but I'd like to see how others come up with a solution as well. Thanks guys/gals.

Hi, i would appreciate if any1 can give me a link to a website where i can download experimental videos/clips. I only know youtube but i do think i can go with any other website as well.

What would the electron configuration (complete or abbr. which ever is easier to make the point) of Ga+3, Fe+2 and +3, and Zn+2? Why does zinc not just lose one electron and have a half full shell? I'd appreciate any explanation on how to predict ionization!

I was practicing a titration lab today that I have to do next week. I was titrating HCl with NaOH from a buret. Using an indicator to obseve the endpoint, I found that 18.32ml of NaOH was needed to react with 25ml of HCl. The concentration of the NaOH was .08045 M, and I needed to find the concentration of the HCl. Using the equation [math]M_1V_1 = M_2V_2 [/math] and converting the ml to liters, I found the final concentration of NaOH was .1277 M, and so I assumed that the HCl would be of the same concentration, but I'm supposed to get .05927 M for HCl. For M1 I have .08045 M NaOH, V1 is .0495L, what I started with, and V2 is .03118L, what I had left. I'm not sure if I'm …

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the zinc atom is smaller than the Ca atom, yet Calcium has a higher atomic number?

What kind of math overall do you use as a chemist? What would you say would be more important to learn in regards to math as a chemist, for instance, linear algebra or calculus? Thanks in advance.

Hey, I'm new here and I didn't really know where to ask this question. I figured that since we breathe out CO2, then this might be a question for the chemistry catagory. So anyway, I'm wondering why steam comes out of my mouth when I sqeeze the gas inside of my mouth. It could be oxygen that I'm sqeezing, but it could also be the CO2 that I'm squeezing too. For all of you who are wondering, to make the steam come out of your mouth, fill your mouth with some type of air, then puff your cheeks out as if you are playing the trumpit. Then softly and slowly open your lips. Some type of steam-looking gas will come out. Why is that? Thanks in advanced, gu…

Hey everyone i was just reviewing chemistry for a class i am going to take next semester and i came upon some questions i am trying to solve which i think might be right but i am not sure. 1.) The rate constant for the decomposition of N205 at 70 celisus is 6.82x10-3s-1 N2O5(g)-->2NO2(g) + O2(g) a.) what is the rate law of this reaction? be sure to include the value of the rate constant in this expression. *my answer* rate=k[NO2]2[O2] since NO2 is 2 and O2 is 1 overall the rate law is 3. I said the rate constant is 6.82x10-3s-1 since that is what it was for N2O5. b.) what is the half life of this reaction if the initial conce…

sorry if this is so stupid, i dont start chem until next year. but how do scientists determine the molecular formula of chemicals? for example, how do scientists know that water has two hydrogen atoms and one oxygen? or lets pretend glucose is an unknown substance, how would a scientist find out it has 6 carbon 12 hydrogen 6 oxygen?

i own a dog... i would rather like to know how one could go about neutralising urine (and whatever else is in the urine) so that at least the resultant no longer looks or smells like it. by neutralise, i probably dont mean the typical chemistry terminology ... i really just want to get rid of the smell .. are there any house hold products that can achieve this task? thanks a lot

I was wondering if someone could help me out with these two equations, somehow I cannot manage to balance them properly... 1)CrO4^2- + Fe^2+ --> Cr^3+ + Fe^3+ (in acidic solution) 2)MnO4^- + ClO2^- --> MnO2 + ClO4^- (in basic solution) I'll really appreciate any help, Thanks!

Many of the aquarium water treatment products use sodium thiosulfate to remove harmful chlorine/chloramine. But some products also bind the ammonia that splits from chloramine into a harmless compound, which is still available to plants and bacteria. Does anyone know what the chemical is that does this?

Hi, well i have a few questions to ask so i will number them up. 1. 'The gaseous oxides of nitrogen have positive enthalphy changes of formation. which factors are most likely to make the most significant contribution to these enthalphy changes?' 2. ' There was this question in exam which had 3 options and all three,first and second, second and third or the first only is correct. The question gave a table as. Element X C Si Ge bond length X-X/nm 0.154 0.234 0.244 the question was: Why does the bond length increase down the group? the options were: 1. Orbital ov…

What chemical similarities are there between reactions of elements with water and reactions of elements with acid? How would you explain the difference in reactivity between an element in water and an element in acid?

I wasn't sure where to put this thread.. But anyway.. Just wondering if a pharmacology course is difficult? What all is involved in it? Like..is it something that would be fine to take as an ONLINE course?

Hi everyone, I've been told by my tutor that this formula: Na2S2O3(aq) + 2HCl(aq) → S(s) + SO2(g) + 2NaCl(aq) + H2O is incomplete as it doesn't consider the effects of heat on the collisions of particles. I know what the effect is, but is she suggesting I represent heat in the equation itself? I've looked all over the net for something to give me a clue - but can't find it! Could anyone help? thanks Gav