Recent content by demander

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    Understanding Successive Dilution in Laboratory Experiments

    Yeah silly me, I need new glasses the real results are for first dilution: Ca = 2.421 mg/L and K = 9.424 mg/L. I switched them around for some reason I guess I was my biggest enemy in all this process.
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    Understanding Successive Dilution in Laboratory Experiments

    That you pointed is what is annoying me. that is why I think I must be doing something wrong. Ca must be way less than Mg and K. K is much more present in salt than Mg. first Bold: My mistake in the first mention, it was indeed 20 ml not 5 mL. we indeed started with 5 for Ca, but Ca was too...
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    Understanding Successive Dilution in Laboratory Experiments

    I am afraid I am doing something really wrong, I would thank if somene could see what may I be doing wrong. I started with the second dilution, the number of moles of Mg, K and Ca present in 5, 2.5 and 20 mL is assumed to be the same after the dilution to 50mL right, only concentration changed...
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    Water molecules effect on Hydrogen bonds in precipitation

    sorry bad English of my part. Yeah what I write sounds like the pH was too high and I on top of that added a base, my bad. What I was trying to say is, when I was studying the type of solution to prepare for the tests, I saw the pH level tends to be around 6 so I was expecting to have that pH in...
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    Water molecules effect on Hydrogen bonds in precipitation

    Cheers everyone. Can the amount of water molecules added to a solution impact the formation of a salt with its ions mainly bonded through hydrogen bonds with electrostatic like behaviour? Let me give Some background to the question first: I am studying the precipitation of Phosphorous(P) as...
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    Why In Struvite formation HPO42- is favored over PO43-?

    Thank you DrDu, I was so focused on Phosphorus I didn't thought to remember the NH4+ turning to NH3 an evolving from solution. That is an inteteresting value. What expression(s) did you use to get there to this sum of Pkas I don't remember this experession(maybe because I was too many years...
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    Why In Struvite formation HPO42- is favored over PO43-?

    Cheers community, I have been studying the Struvite formation from respective ions. Being the general formula for Struvite MgNH4PO4.6H2O I intuitively tought the reaction would be Mg2+ + NH4+ + PO43- + 6H2O↔ MgNH4PO4.6H2O. However from literature and from practice, not only the optimal pH seems...
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    Help in deducing a equation for Neutral red

    http://jchemed.chem.wisc.edu/Journal/Issues/2001/Mar/PlusSub/JCESupp/JCE2001p0349W.pdf that's the link to the article... i put the pages needed in the attchments if you can't acess the journal
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    Help in deducing a equation for Neutral red

    well i really had a doubt about that... cause i think In the two case, the absorvance is given in function of total conectration... these equations are giving in a protocol of the journal of chemistry, but they simnply say... we used this 4 equations and arrive to this :S I couldn't seem to...
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    Help in deducing a equation for Neutral red

    The backwards trying was easy... but if i try to do the reverse... the multiplying term is not to clear how it showed off from the equations i give cause backwards the final term is: \frac{C_{NR}(\epsilon_{NR}-\epsilon_{HNR})}{C_{HNR^{+}}(\epsilon_{NR}-\epsilon_{HNR})}} so the thing i don't...
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    Help in deducing a equation for Neutral red

    Hi to all, hope you can help me with a problem that took me almost all the week Homework Statement To find The Pka of Neutral Red, i had to use this expression \frac{A-A_{HNR}}{A_{NR}-A} So Now I Have to show that \frac{[NR]}{[HNR^{+}]}=\frac{A-A_{HNR}}{A_{NR}-A} i tried backwards and i did...
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    Chemistry Chemistry Organic Molecule Drawing Program

    a program that is good to and is freeware i think is ChemSketch from ACDLabs i ha da link but i don't know where i put it lol is good to simple quests, the hirgher limitation is to draw multi aromatic compounds like 3 conjugated benzenes
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    Physichal chemistry ideal solutions

    by the way connected with this same question what is in fact the(or an) azeotropic point? i see in many places but was all a bit confusing seem that is the pressure at what the boiling doesn't change anything... but how can this be aplied to activity coeficients ?
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    Physichal chemistry ideal solutions

    ok thanks very much for the help, was really really usefull:smile:
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    Physichal chemistry ideal solutions

    x and y are exactly what you said mole fraction of each component( liquid (x) vapour (y) P is the vapour pressure of the diferent compositions of liquid and gas of a mixture of ethanol + chlorofom at 45ºC (318,15K), don't know if this last line matters for it or not but i put it to complete...
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