Paravani Posted July 18, 2014 Posted July 18, 2014 (edited) Hi, All! Gotta pack, moving to the east coast in a couple days, so too much to do to post much more right now. I'll be back in the first week of August... but I just had to respond to these posts: I may have misrepresented what I was thinking when I said that. My thinking was how I appreciated that he referred to the periodic table and built molecular weights by adding the atomic weights, to show the weight in grams of a mole of that molecule (based on Avogadro's number; pardon misspelled words). When balancing equations and formulas, once we know the mass ratios of the parts, we can apply those ratios to scale up or down to match the quantities of our starting materials or the mass quantity of the end product we desire. Very useful. Thanks again. WSM Thanks, WSM! Glad to be of help. The weight percent thing was perfectly correct, and is quite useful to know how to do. I was referring more to the use of K2O and P2O5 in NPK ratings instead of percent by mass of potassium itself. Weight percent to me would be much more useful and logical, but alas, I don't make the rules, just follow them. If you tried to find KNO3 with 13.4-0-38.7 NPK rating, you'd have trouble. It seems bags are starting to list both though. I honestly didn't even notice that I was using slightly different masses for potassium nitrate and potassium itself until Paravani made a point of it. Working with chemistry all the time, these are just numbers I have at the top of my head. I was also really trying to avoid using the term mole, but I couldn't help it. My hands were unwilling to listen to my brain to type that one molecule of KNO3 weighs 101.1g for simplicity sake. We're glad you're here, Mumbles, even if your posts ARE more technical than most of us can follow. It does show a little bit that you're a professional in the field of chemistry. I'm strictly amateur -- took a year of chemistry two decades ago, and only use it now and then when I want to figure something out, or when I want to explain something to a kid I'm tutoring. Thus my back-of-the-envelope rough guesstimate, and my cavalier disregard of moles. (Moles really aren't useful by themselves, you know -- they just add an extra set of steps to the calculation. What is most useful is what moles represent -- the principle of a balanced reaction, with the same number of atoms on each side.) I hope that my chemistry-amateur posts help average members here understand how to do these kinds of calculations even if they've never taken chemistry, or don't remember what they learned. I'm used to talking about chemistry with people who don't get it at first... and I'm aware that indeed, most people DON'T understand at first how to use chemistry even if they've taken a course in it and done well. They just learned enough to regurgitate, to earn the grade, and never thought about it again. However, fireworking is ALL about chemistry. We can try to guess whether a little more of this or less of that chemical would make a composition burn hotter or slower, brighter or faster... but stoichiometry (balanced equations for the reactions) will tell us exactly what the ideal proportions are, and even give us hints which ingredients can be increased or decreased to speed up or dampen the reaction. But balanced chemical equations for fireworking can sometimes be difficult to find... and that's when we all really appreciate members like you, Mumbles. I know a bit about chemistry, and how to explain it to people who know less than I do... but I don't know which reagents will produce which reactants, or how to figure out what the products of a pyrotechnic reaction will be, given a list of the chemicals in the formula. That's where people like you can be extremely helpful to folks like us. For instance, I've been having trouble finding a balanced equation for BP combustion. It starts out KNO3 + C + S + O2 --> ? ... and then? CO2 + what? What are the exact products of this reaction? How can we tune the empirical formula for BP (75/15/10) for maximum efficiency? I also don't know how to calculate how much energy is released by an exothermic reaction, either in calories or joules. Can you give us a quick refresher course in that? I'm sure it will come in really handy! Thanks in advance for letting us pick your brain! ;-D -- Paravani Edited July 18, 2014 by Paravani
WSM Posted July 24, 2014 Posted July 24, 2014 Before I knew about Lambentveteran I purchased some KN03 from Seed Ranch. When I got it the bag showed a label that said:*********Greenhouse Grade (KN03) Potassium (K) 38.04%Nitrogen (N) 13.5%Soluble Potash (K20) 46.20%Nitrate-nitrogen (N-No3) 13.5%Net Weight 2 LBS**********Is this what I need for BP. This is the first time I used this company because of the price. Mill it fine and it will be great. WSM
cecil Posted August 31, 2014 Posted August 31, 2014 Hi, All! Gotta pack, moving to the east coast in a couple days, so too much to do to post much more right now. I'll be back in the first week of August... but I just had to respond to these posts: Thanks, WSM! Glad to be of help. We're glad you're here, Mumbles, even if your posts ARE more technical than most of us can follow. It does show a little bit that you're a professional in the field of chemistry. I'm strictly amateur -- took a year of chemistry two decades ago, and only use it now and then when I want to figure something out, or when I want to explain something to a kid I'm tutoring. Thus my back-of-the-envelope rough guesstimate, and my cavalier disregard of moles. (Moles really aren't useful by themselves, you know -- they just add an extra set of steps to the calculation. What is most useful is what moles represent -- the principle of a balanced reaction, with the same number of atoms on each side.) I hope that my chemistry-amateur posts help average members here understand how to do these kinds of calculations even if they've never taken chemistry, or don't remember what they learned. I'm used to talking about chemistry with people who don't get it at first... and I'm aware that indeed, most people DON'T understand at first how to use chemistry even if they've taken a course in it and done well. They just learned enough to regurgitate, to earn the grade, and never thought about it again. However, fireworking is ALL about chemistry. We can try to guess whether a little more of this or less of that chemical would make a composition burn hotter or slower, brighter or faster... but stoichiometry (balanced equations for the reactions) will tell us exactly what the ideal proportions are, and even give us hints which ingredients can be increased or decreased to speed up or dampen the reaction. But balanced chemical equations for fireworking can sometimes be difficult to find... and that's when we all really appreciate members like you, Mumbles. I know a bit about chemistry, and how to explain it to people who know less than I do... but I don't know which reagents will produce which reactants, or how to figure out what the products of a pyrotechnic reaction will be, given a list of the chemicals in the formula. That's where people like you can be extremely helpful to folks like us. For instance, I've been having trouble finding a balanced equation for BP combustion. It starts out KNO3 + C + S + O2 --> ? ... and then? CO2 + what? What are the exact products of this reaction? How can we tune the empirical formula for BP (75/15/10) for maximum efficiency? I also don't know how to calculate how much energy is released by an exothermic reaction, either in calories or joules. Can you give us a quick refresher course in that? I'm sure it will come in really handy! Thanks in advance for letting us pick your brain! ;-D -- Paravani You might find this helpful: http://crescentok.com/staff/jaskew/TAH/projects/chemistry/HSchem.htm cecil
smokeytech Posted September 9, 2014 Posted September 9, 2014 just out of curiosity, how much is the technical grade? http://www.mypixshare.net/files/img/user_uploads/displayimage.php?id=jvg4v495nn5s3665046.gif
WSM Posted September 22, 2014 Posted September 22, 2014 just out of curiosity, how much is the technical grade?http://www.mypixshare.net/files/img/user_uploads/displayimage.php?id=jvg4v495nn5s3665046.gif How much what? Your question is unclear (are you asking price, weight percent or something else?). Let us know. WSM
MWJ Posted September 22, 2014 Author Posted September 22, 2014 Lambentveteran has the best grade of KNO3 and price that I have seen. If thats what your asking? PM him for questions
dagabu Posted September 22, 2014 Posted September 22, 2014 Lambentveteran has the best grade of KNO3 and price that I have seen. If thats what your asking? PM him for questions Who?
Mumbles Posted September 23, 2014 Posted September 23, 2014 http://www.amateurpyro.com/forums/user/18461-lambentpyro/
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