Give two reasons, why you would not expect to produce a 100% yield of alum crystals?
478287
No reaction goes to completion, and entropy dictates there will be loss.
588486
If you mill Aluminum plates to a very fine precision, and then stack the plates together they will become difficult to dislodge from each other.  The reason is not due to suction.  It is due to covalent bonds forming between the two slabs of metal!  Hard to believe isn't it!  I thought so too, even when I got a chance to see it first hand.
73838
Its' probably a rounding error. It would depend on which masses for the elements you use, how precise you want to be.
806350
Could be a lot a reasons, you spilled some. If its an organic reaction you never get a 100% completion, there are always some unreacted materials left.  Thats just how organic are. if you filtered it then you lost some through the filter and and on the paper.
879313
Absolutely correct! I second the motion.\n\nThere is never a 100% guarantee of anything in mineral prospecting. Even with a good site analysis and positive assay results, it may be there in commercial amounts, or just enough for collector's amusement.
279568
Link:\n\nNo idea how to produce more...
174049
I'd like to encourage you to learn chemisrty instead. The alchemists tried and tried to make lead into gold and similar things. Now we know that it cannot be done. They wasted their time. Don't waste yours. Learn and make something of yourself.
1027970
Simply that during the induction period, the actual concentrations may not be 100% homogeneous and the rates will increase of decrease from theoretical.  This is much more important with macromolecules, but can be seen in other cases.  See\n\nwww.uem.mz/faculdade/ciencias/ ciencias_revista/textos/elalves.pdf\n\ndx.doi.org/10.1063/1.1954769\n\nwww.platinummetalsreview.com/ dynamic/article/view/50-2-54-63\n\nwww.citadel.edu/chemistry/scas2005.pdf
374481
It is quite normal. I use this process a lot for creating hydrogen in my lab for demonstrations. I fill up balloons and blow them up. Students love it.The black precipitate is a complex hydroxide of sodium and aluminum.
736486
Recrystallization in water can have a good yield of product if the compound you are using is soluble in water. Water would not be a suitable solvent in all reactions because of its high boiling point I think.  It is important to choose a solvent which will not dissolve the substance at room temperature so that the pure crystals may be recovered. So it affects the yield of the crystals also. \n\nThis question did inspire me to research it because I couldn't recall the exact answer...though I'm sure we discussed it in class......\n\nA good solvent for recrystallization must:\n\n1. not react with the desired solid \n\n2. be easily removed from the desired solid \n\n3. dissolve a relatively large amount of desired solid at high temperatures (usually the bp) or not at all) \n\n4. dissolve impurities at all temperatures or not at all \n\nFrom what I read water is usually not good as a solvent by itself because it does not meet all of the above requirements....BUT as most compounds tend to violate one or more of these as well, water is often used in conjunction with other chemical compounds to form a solvent pair. Water IS a good solvent in the recrystallization of acetanilide due to the solubility of it in water. You would have to use the Merck guide to see the solubility of a compound in water to determine its suitability as a solvent.
68849
Gold is usally found in veins in mines.  This is after yearssssss of a couple different mixtures that could happen with elements and combounds that get really complicated an messy.  But, scientist have created a particle accelerator that shots atoms at one another to created a desired "pure" element, but this mechine is about the size of a football feild or so and the chamber that the bombarding happens in is a room as big as your average class room and it only produces just enough gold to little dust the tip of a sewing neddle.
418782
Well depends on the amount of crystals you want, but yes you can. In fact I did it my self and obtained a few crystals.
174475
mix it...let NaCl dissolve in water...then let the mmixture evaporate or perhaps bring the mixture into a boil 'til you can see the formation of crystals...   try it... i've encountered such experiment in my chemistry class... im not quite certain of the procedures though...it's two years ago...cant remember it well...^_^
538542
though there are many, one of them is:\niceland spar crystal\none reason can be due to the harmonicity of vibrations of the atoms of the substance when their kinetic energy increases
583380
A crystal is non-living, does it make any sense for it to grow, as they do, 'knowing' what color to be, what shape and size and how many facets and what angles to have and what clarity and hardness to have and what refractive index to have and give off little baby crystals which will grow up in the likeness of the parent. You could liken our DNA to a kind of protein crystal, It 'knows' what to do because the data is contained within its molecular structure. There is no reason for it so it makes no sense but none the less, it occurs naturally. We have to accept that we were created by our genes as a mere vehicle for its own use.
527447
Ive been a gem cutter for nearly 35 years...Gunner is right on his points about opal, but your case is a little different with what you have...If you would like to email me at tahoeman_69@sbcglobal.net or IM me at tahoeman_69, I would be happy to discuss everything you would like to know...It is really more involved than I can describe here and I think it would help to uncomplicate the process if we talked via messenger...
900927
Well, in things like pegmitites, late stage crystalized rocks, you can have very high amounts of incompatable elements, like Li, Au, Ag, B, Zr, and many more.  That's why you get minerals like beryl, lepidolite, tourmaline, etc.