if i have a 80% purity, is that a fairly pure product?what is the range for good/bad purity?...Thanks?
140874
The question is unanswerable. It depends entirely on what product you are talking about and what the contaminants are. \n\nAs an example, there are garden herbicides available that can produce dioxane as part of the manufacturing process. Dioxanes are not nice substances and can cause cancer and birth defects. Would you be happy if the product you were spraying on your garden was 1/5 dioxane? I wouldn’t be, nor would the EPA. In cases where the contaminant is highly problematic the absolute minimum purity is normally measured in parts per billion. Or to put it another way 99.99999999% pure would barely pass muster.\n\n\nContrast that with something like gravel. Gravel is important for construction work and landscaping and it’s sorted by sieving. You don’t want to buy gravel for a pth and discover it contains a lot of sand, but you wouldn’t want to but sand for making concrete and discover it contains a lot rocks either. Gravel is sold by size. But if someone bought 3inch gravel that contained 20% of 2” grains and a further 20” of 4” they really wouldn’t care too much. The difference is so slight that so long as most of it is the right size it makes no practical difference. In cases where the contaminants present no serious problems the purity can be as low as 40% without anybody caring.
1117422
Just curiosity: given by a boyfriend or girlfirend?\nAlso how old are you both. Then I will be able to give some answer about safety.\n\nOf course, you have no lab to make analysis what is really in it...
304287
This is called Base line correction.\nYour solvent may be having some absorption, or the impurities in it may be having some absorption..so to measure your compunds absorption exactly, you need to take the solvent (n whcih you are going to dissolve your compound later) and do this base line correction.\nIn a way you are telling instruments "NOT TO WORRY ABOUT THESE ABSORPTIONS"\n\nThats it\nYou got it?
1151385
I am interested, but I would want to know:\na) Where is your processing plant located?\nb) Who would pay the transportation/shipping costs to Calif. ?\nc) How is it packaged for shipping ? Plastic drums?\nd) How has it been processed, liquified ?\ne) What is the salt (NaCl) content ?\n  Your question gives me very little information to satisfy my needs.
559771
I have heard that smcin728 pixy dust is pertty good stuff.  And hardly any side effects.  My suggestion is to STOP asking so many questions.  LOL.  Just a suggestion.  j/k :)
413258
It's no use trying to find that out. Those conditions are to be fully controlled to get "non-colored" products.\nAnd be careful with what you use in food products!!
111661
there are different levels of purity of water and other solvents. the more pure the solvent is the more expensive.\nfor most introductory labs or where the results aren't critical then walmart quality distilled or deionized water is ok.\nfor other purposes you'd want to use the really good stuff.
783521
Anything from the periodic table is pure. these are all basic elements that can't be broken down into other elements. examples: hydrogen, nitrogen, iron, zinc and gold.\nclick here for the table: http://www.chem.qmul.ac.uk/iupac/AtWt/table.html
844268
how were you measuring the pH? if it was a pH meter maybe it wasn't calibrated correctly/ recently?? or if it was with litmus paper.... maybe it went bad? I'm not sure if it can... check and see if there could have been an expiration date. i don't think temperature would have that drastic of an effect unless you did the experiment at pH7 and a seriously high (like about 60C) temp and the other ones at room temp or 37C (body temp)... sorry i cant help anymore then that, that's very strange!
572872
Lets say you have x ml of Fe2+ salt which required y ml of MnO4-. Now, the eqn. is\n\n5Fe2+ + MnO4- +8H+-> Mn2+ + 4H2O + 5Fe3+\n\nSo, assuming y ml contains Y mol of MnO4-, Fe2+ oxidised is 5Y mol.\n\nNow x ml corresponds to X mol.\n\nSo, purity is (X-Y)/X * 100 % pure Fe2+
256530
I can't imagine that it is very good. I would try and clean out the container on a regualr basis so their is no build up of anything.
16164
The instruction is not correct because the total volume yielded when you mix 100ml of concentrated solution and 900ml water will be somewhat less than 1000ml. The concentration will be slightly higher than 1.0M\n\nThe correct procedure is to take a 1l volumetric flask  and add the concentrated solution to about 800ml water, then fill up to the mark.
1117539
2400mg Max! Its hard to do coz all process foods have salt.Dont add salt to anything and read labels carefully.Cheese pizza and hamburgers are loaded with salt!Forget fish and chips all together.Look at bread labels, cottage cheese,even yogurt and you will be surprised at the amount of salt they have! The AMA is trying to force the FDA to add a new label to foods.I hope they can do this coz it will be a great help.
676978
you can only dilute it w/v as it is a solid. Just take 10gr and dissolve it in about 50ml distilled water, then make up to 100ml when it has cooled.
125676
a fairly lengthy description can be found at\n\nhttp://apps3.fao.org/jecfa/additive_specs/docs/0/additive-0465.htm
889851
Your unknown compound might be an impure substance.  The impurities will skew the melting point.  You should find out if the substance is pure or not.  Pure substances (that is, with nothing else mixed with them) will have a narrow ranging in which they melt, for example, pure Naphthalene melts between 83-85 Celsius.
48317
I don't know what you're rinsing so it's hard to answer this question. \n\nIf you have 10,000 bacteria in a 1.0 mL sample and your first rinse removes 99% of them then you still have 100 left (more than enough to make someone sick if it's a nasty pathogen.) If you rinse again and remove another 99% then you're down to 1 bacteria per mL. Rinse a third time and you can reduce the count to 0.1 bacteria per mL. \n\nThe result is you've reduced your starting count by 6 logrithmic. That is an acceptable reduction from a food processing standpoint. \n\nThe numbers I gave are totally arbitrary since I don't have any specifics. Its possible that each rinse removes more (99.9) or less (90% or lower)bacteria.