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(Updated - see end, below)
If you've ever wanted to play around with sodium acetate, but you're too much of a nerd to simply go online and buy some from a chemical supply house - noooo, that'd be too easy, you want to make it, from scratch - then this instructable is for you.
Inside, I show the whole process, from baking soda and vinegar, through concentration and filtering, to final crystallization.
(Please note that you, not I, explicitly assume all risk associated with playing with chemicals, fire, or hot things. Use common sense. If you're not an adult, enlist the help of a parent. If you're an idiot, close your browser now before you burn yourself. And regardless, by reading any of the suggestions contained herein, you implicitly assume full responsibility for any and all accidents, burns, lacerations, ruptured spleens, loss of consciousness, death, shin splints, hangovers, spurned advances, or insolvency that may result. Seriously... use your brain.)
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Update: When I first wrote this Instructable, I somehow got it in my mind that acetic acid had a boiling point that was slightly lower than water - this is incorrect! Acetic acid (ethanoic acid) has a boiling point of 118.1 C. This may change some steps and I may amend the instructions after I've had a chance to play with a few things; for now, though, when I talk about acetic acid boiling off in some of the steps, take it with a grain of salt (or at least sodium bicarbonate). :-)
If you've ever wanted to play around with sodium acetate, but you're too much of a nerd to simply go online and buy some from a chemical supply house - noooo, that'd be too easy, you want to make it, from scratch - then this instructable is for you.
Inside, I show the whole process, from baking soda and vinegar, through concentration and filtering, to final crystallization.
(Please note that you, not I, explicitly assume all risk associated with playing with chemicals, fire, or hot things. Use common sense. If you're not an adult, enlist the help of a parent. If you're an idiot, close your browser now before you burn yourself. And regardless, by reading any of the suggestions contained herein, you implicitly assume full responsibility for any and all accidents, burns, lacerations, ruptured spleens, loss of consciousness, death, shin splints, hangovers, spurned advances, or insolvency that may result. Seriously... use your brain.)
---
Update: When I first wrote this Instructable, I somehow got it in my mind that acetic acid had a boiling point that was slightly lower than water - this is incorrect! Acetic acid (ethanoic acid) has a boiling point of 118.1 C. This may change some steps and I may amend the instructions after I've had a chance to play with a few things; for now, though, when I talk about acetic acid boiling off in some of the steps, take it with a grain of salt (or at least sodium bicarbonate). :-)
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Signing UpStep 1Preparation
We'll be making approximately 330 mL (or 11 fl oz) of supersaturated solution.
You will need the following items:
- One 16 oz box of baking soda (sodium bicarbonate)
- One gallon jug of distilled white vinegar (acetic acid)
- Clean pot for boiling (5.5 Qt or larger)
- Another clean pot for filtering (4 Qt or larger)
- Pack of coffee filters (basket style, not funnel shaped)
- Small wire mesh strainer (big enough to hold a coffee filter)
- One cup measuring cup for pouring hot solution through filter
- Large clean cooking spoon for removing samples while boiling
- Small clean dark dish (e.g. custard cup) for holding samples
- Clean jar to hold final solution
- Distilled water (in case you over-boil the final solution - see step 14)
Optional Items - this is for a purification step that I found I needed (see step 6 for an explanation). If you decide to do this too, you'll need:
- Two cups granulated activated charcoal (from drug store or pet supply)
- Lab stand with burette clamp (if you have this)
- Funnel (if you have a lab stand; should be big enough to hold folded coffee filters - see step 10)
You will need the following items:
- One 16 oz box of baking soda (sodium bicarbonate)
- One gallon jug of distilled white vinegar (acetic acid)
- Clean pot for boiling (5.5 Qt or larger)
- Another clean pot for filtering (4 Qt or larger)
- Pack of coffee filters (basket style, not funnel shaped)
- Small wire mesh strainer (big enough to hold a coffee filter)
- One cup measuring cup for pouring hot solution through filter
- Large clean cooking spoon for removing samples while boiling
- Small clean dark dish (e.g. custard cup) for holding samples
- Clean jar to hold final solution
- Distilled water (in case you over-boil the final solution - see step 14)
Optional Items - this is for a purification step that I found I needed (see step 6 for an explanation). If you decide to do this too, you'll need:
- Two cups granulated activated charcoal (from drug store or pet supply)
- Lab stand with burette clamp (if you have this)
- Funnel (if you have a lab stand; should be big enough to hold folded coffee filters - see step 10)
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I'm skimming, appreciate the cool instructable :)
--PC
Heres how 4 attempts ended in my case, help me please.
Good 'Ible though! :D
can you eat it?
Sodium Acetate is C2H3NaO2, molar mass 82.03g; density 1.528 g ml ^-1
Acetic Acid is C2H4O2, mm is 60.05, density already given above.
Sodium Bicarbonate is CHNaO3, mm 84.01, density 2.173
Water: If you (anyone, not ryguy428) don't know formula or density of water, you're NOT ready to try chemistry. Or graduate from secondary school. Or vote. Molar mass is trickier - it's about 18.0152833 - depending on a few things... ;-)
Rxn: CH3–COOH + Na+[HCO3]– → CH3–COO– Na+ + H2O + CO2
Do the molar balance, substitute for density, and you'll get theoretical yield.
(Hint: 84g of soda should give about 82g of sodium acetate. If you were using 8% vinegar, you'd need about 750ml. If you can make that calc come out right, do it for 5% and you'll have your answer.)
But thanks for working out the stoichiometry anyway!
A tad harsh about the assumed knowledge though, there are lots of bright and creative people who don't need that info.
What things did you have in mind for the water that would affect the mass within the accuracy limits and significant figures of your other data?
B) I'm reminded of the story that someone asked Einstein what the quadratic equation was and he (supposedly) said "I know where to look it up - why should I bother memorizing it?"
<inappropriate political rant> I shudder to think, though, that one can get through high school without knowing that water is H2O, and the absolute *basics* of the metric system (i.e., that mass, length, and volume (and, in fact, temperature and energy, by extension) are tied together by the single, simple fact that 1 cc of water weighs (masses, actually) one gram. Now, I was being a wee bit sardonic, but -- heck, the U.S. makes people applying for citizenship learn all kinds of stuff that (generously) 40% of voters couldn't answer. I sure don't want people voting on global warming, stem-cell research, and energy policy, if their scientific knowledge base doesn't include the absolute scrapings from the bottom of the barrel... ;-) </ inappropriate political rant>
More fairly - I liked Heinlein's quote (Google "specialization is for insects"). IMHO, and only my opinion, no adult in the modern world should be considered educated without a grasp of some plurality of some basic knowledge set. Defining that is politically 'difficult' - but I stand by the concept:
Things are made of atoms. The earth is round and goes around the sun, because of gravity. Traits that help survival get passed on. Wood burns, which gives light, warmth, and tasty food. Men and women think and prioritize differently. (Some) germs cause (some) diseases. Too much sunlight is bad for you (as is not enough). Stay away from wild animals. Seeds grow into plants, which need light and water. Don't eat wild mushrooms, or build a fire in an enclosed area. Yadda yadda. And water is H2O.
C) Nothing - given your stated constraints. Hence my smiley-face. I was winking at those who'd say something about "well, that's liquid phase - it's more like 0.917 as solid - you have to say at s.t.p. (or, more accurately, at the triple-point). And - what about deuterium content? And never mind supercooling, or allotropic forms....
C : I know, and apologise.
I was baiting you a bit about showing off your (absolutely correct, by the way) knowlege. :)
The constraints in fact were outlined by your good self in terms of the sig. figs., phase and isotopic accuracy you supplied for the other reagents. Naughty of both of us, I apologise. ;)
B : (sorry about the chaotic order, this reply is harder to compose since it's more subjective than A or B!)
An interesting one and, as you say, very subject to opinion.
Being a real "science geek" (also with degree level chemistry) at heart myself I hear and understand everything you're saying about basic knowledge.
However, being in the education biz myself tends to steer me away from giving particular importance to my own skill set and knowledge base.
Indeed, to quote your own words "no adult in the modern world should be considered educated without a grasp of some plurality of some basic knowledge set.", which I agree with but for the sake of argument we could go with the knowledge set allowing us to create works of art or music.
Neither of these knowledge sets requires the formula for water, but I don't think we can eliminate some of our great creative individuals from the voting process just yet!
Having said that, if you have a look at www.senseaboutscience.org.uk you'll see a wonderful teardown of some science "facts" put forward by some our of leading "celebrities"
I certainly grant that most visitors to this site will also veer towards the science geekdom side of things so perhaps your argument stands in many cases, but I still think not all. Perhaps I'm just playing devil's advocate!
So there! *puts away his own soapbox for the time being*
Apologies to anyone I've bored with my own rant :)
"also with degree level chemistry" -- whoops! I never said that. In fact, I've had only 2 chem classes, and that's generous - one was junior high and the other high school, and I didn't excel at either. I'm self-taught over the last 4 years or so, with some help from a PhD friend or two and a lot of journal articles....
I agree fully about not eating too much of one's own dog food. My educational and work background is management (MBA) and IT, so my criteria also include basic computer & Internet skills, balancing a checkbook, a rudimentary grasp of economics ("supply and demand", as Father Guido Sarducci's 5-minute University had it), and how interest works.
People ought to have some clue about atoms, electricity, magnetism, light/EM radiation, the Big Bang, stars, and the universe. Ditto nutrition, what a liver's for, vitamins (esp. folic acid), and first aid. Ditto basic literacy, numeracy, and communication skills. Ditto basic geography, history, political science, philosophy, literature, art, and music.
I'm also a big fan of ideas like: everyone should learn to speak another language, play a musical instrument, (try to) get good at a sport, travel to foreign countries, hike/camp in the wilderness, go sailing out of sight of land, summit a mountain, be able to cook one good meal, etc.
OK - I've now fully digressed into a complete rant about how the entire human race should conduct its affairs. So - I'll see your apology, and raise you. ;-) I realize this is not the forum for my opinions on this -- I'll take it offline henceforth.