Proportions for a Chemical Solution
Date: 6/24/96 at 13:47:3 From: William B. Fair Subject: Formula for a Chemical Solution I need some help in my basic math on mixing up percentage formulas. For example, if I want a 10 percent solution of a particular chemical that comes in powder form what would be the formula to solve this? I've used amount desired times percent desired divided by percent on hand for all of my liquid formulas, but now that a powdered chemical has come into play I'm sure you just don't use an equal weight in grams, say 10 grams in a 90 ml. beaker, and expect to get a 10 percent solution. Or is it that simple? I hate to take your time up with something so basic, but other than to the library and research this out I had hoped that the Internet could help me out, and you were my first choice. Thanks - Bill
Date: 6/24/96 at 20:15:41 From: Doctor Anthony Subject: Re: Formula for a Chemical Solution I am not a chemist, but if you are mixing chemicals by weight, then for a mixture containing 10% of a particular substance, in every 100 gms of the mixture, 10 gms will be of that chemical. If you are mixing by volume, then clearly you would add 10 ml to 90 ml to get 100 ml of the mixture. I note that you were confusing mass and volume when you suggested 10 gms and putting this into a 90 ml beaker. I think you should consult a chemist as to whether it is by mass or volume that you are meant to be working. If it is by volume you would doubtless first dissolve the chemical at at a quoted mass for a given volume of water, and then mix this liquid by volume with the other chemicals in the ratio 1 : 9. -Doctor Anthony, The Math Forum Check out our web site! http://mathforum.org/dr.math/
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