Recent content by demander

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.

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...

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...

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...

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...

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...

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...

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

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...

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...

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...

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

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 ?

ok thanks very much for the help, was really really usefull:smile:

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...