Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 


Forgot your password?
Close
typodupeerror
×
Education Science

The Delights of Chemistry 133

Posted by Hemos from the ka-FOOM dept.
Dan Ormsby writes: "No news on this site, just great photos of chemical phenomena along with instructions on how to perform them yourself. Don't try this at home!"
This discussion has been archived. No new comments can be posted.

The Delights of Chemistry More

The Delights of Chemistry

Comments Filter:
  • Why do we get instructions on how to do it?
    • Obviously you arent supposed to try this at *YOUR* home. Try your friends home, instead!

      Hey Tom, watch this!*

      *Also spoken before many Darwin Award candidates last moves.

    • to make sure that if you have a bottle of sulfuric acid, nitric acid and some glycerol, you don't want to accidently mix the acids in a 3 to 1 ration, and then inadvertently add the glycerol. don't breath the resulting product, since it vaporizes eaily and is an oft-used medicine for heartpatients. It widens bloodvessels. it is also rumoured this stuff makes a mighty good explosion. The exact product left as a reader's exercise...

      //rdj
  • Christ, what kind of childhood would I have had with THAT kind of advice?
  • how long before we see Ascii art trolls of the "Golden Rain" rxn?


    insert your own lewd reference here.

  • This will be /.'ed before you can say H20

  • Google's cached site (Score:1, Informative)

    by At000miC ( 261392 )
    http://www.google.com/search?<br>hl=en&safe=off&q= cache:U69NL26L50Y:www.chem.leeds. ac.uk/delights/+&spell=1

    • Re:Google's cached site (Score:3, Interesting)

      by smunt ( 458722 )
      I think slashdot should have such a caching service too.

      *NEWS* is almost never in google's cache.
  • Just how many of these experiments are copyrighted? i don't wanna pay the powers that be for the privilege of a cheap and easy chemical burn.
  • and I already checked for a google cache. Too bad Hemos didn't give us his own witty commentary, so at least we could make fun of that while waiting for the site to go back online.

  • Great ways to get kids into science (Score:3, Insightful)

    by RollingThunder ( 88952 ) on Thursday August 30, 2001 @06:27PM (#2237015)
    I remember finding a book of chemistry experiments, and being fascinated with what I could do with just mixing a couple things.

    Not simple stuff like "wow, vinegar and baking soda" (although kitchen chemistry is very cool), but "wow, battery acid, zinc and limestone will make lethal chlorine gas! cool!". (iirc)

    While I don't want MOST kids getting that spin on it (:D), some golly-gee-whiz experiments at a YOUNG age, with some more every year, will help keep them interested in learning. And up here in Canada, at least, we've got a big problem with keeping boys interested in learning. But boys like things that go bang. Simple solution. :)
    • Wanna know how to make chlorine gas quick:

      bleach + ammonia (windex)

      I believe there about a dozen deaths a year of housewives who stumble upon this combination.
      • True, but you get other gasses being released as well at the same time. I recall this experiment was to get (basically) pure chlorine gas, in a controlled manner.
      • That's a commonly held misconception that's almost an outright urban (chemical) myth. I don't know about how many people die because of it, but it doesn't produce Cl2 gas. It produces Hydrazine (N2H2, or H-N=N-H), which mainly used in the space program for short burst maneuvering thrusters on spacecraft, and has been used since the very first US launches at Vandenburg.

        It's bad enough stuff that if you're able to smell it, you've already got brain damage, so there aren't too many people who know what it smells like. If I recall, there was a guy at Vandenburg whose job was to sniff for Hydrazine, but that was a classified project and they could get away with that kind of crap.
        • While it is correct that the reaction between bleach and ammonia forms hydrazine, this is not the most dangerous product. The following reactions are occuring:

          (1) NH3 + NaOCl = NaOH + NH2Cl

          (2a) NH3 + NH2Cl + NaOH = N2H4 +NaCl + H2O

          (2b) 2 NH2Cl + N2H4 = NH4Cl + N2

          Reaction (2b) is a cometing reaction to (2a), and it is actually catalyzed by the formation of hydrazine (N2H4, not N2H2 as you stated). This means that only a small amount of hydrazine is formed.

          The dangerous product in this case is NH2Cl, chloramine gas. This stuff is very bad for your mucous membranes, and can easily kill you when inhaled.

          Hydrazine is dangerous stuff too, though. It is a strong reducing agent, is easily adsorbed through your skin, and it is carcinogenic. I work with this compound in the chemistrylab, and the label says that it's a threat to health and life at concentrations as low as 80 ppm.

        • Ah! The joys of hydrazine. Once, in a college chem lab, I made the mistake of sniffing 2,2-dichlorolphenylnitrohydrazine. It's commonly used to help identify unknown organic chemicals. You combine it with the unknown, and run a whole lot of tests on the resulting compound, and then you run the results though the big CRC book (Chemical Research Corporation) and maybe you'll find out what it is.

          Anyway, I got a whiff of this stuff, and my eyes watered for about ten minutes. It was VERY painful.

          As for memory loss? Well, I have a degree in chemistry, but I can't remember a damn thing about it...

      • bleach + ammonia rxn as an above poster points out does not form Cl2 gas but N2H2.

        I think the problem is that many housewives just don't know their chemistry very well (for shame!). The reaction that produces Cl2 gas and sometimes kills when produced in great enough portion is Bleach + Toilet Bowl Cleanser (like TidyBowl) which often contains hydrochloric acid. It is: NaClO + HCl --> Cl2(gas) + NaOH (aq.).

        This reaction afforded me with endless hours of fun experementation when I found out how to do it as a kid(Cl2 gas has lots of spontaneous cool reactions with common household items).
      • Bleach mixed with brake fluid is pretty good too, lots of smelly smoke.

        Unfortunately, I'm all out of brake fluid just now, and it doesn't work with LHM (trust Citroen to be different, spoiling my fun...)


    • How did you get battery acid, zinc and limestone to make chlorine gas?


      Battery acid is sulfuric acid, H2SO4, zinc (obviously) Zn (provided it's elemental zinc and not oxidized or something), and limestone is calcium carbonate, CaCO3.


      You would get hydrogen gas by reacting sulfuric acid with zinc, and you'd probably get bicarbonate ions (or something like that) by reacting with limestone, but far as I can tell, you wouldn't get any chlorine gas.


      Were you thinking of hydrochloric acid, HCl?

    • Hey, don't knock kitchen science. Burn Teflon®. One of the reaction products is HF, which is deadly in only parts per million. Woo hoo!

      (This is why you shouldn't run coaxial cable through heating ducts. It contains Teflon®. A fire will cause poison gas to be piped throughout the ventilation system. Again, I say, "Woo hoo!")

      Time to get another canary...
      • Teflon is:

        -CF2-CF2-CF2-CF2-...

        Burning Teflon (i.e. reaction with O2) will give you all sorts of toxic fluorinated compounds, but I don't see how you get HF (hydrogen fluoride) out of this.

        • incomplete combustion, impure samples, contamination of the oxygen supply.

          kind of like the question "where do hydrocarbons, sulfates, and nitrates come from when running my car?"

          • where do hydrocarbons, sulfates, and nitrates come from when running my car?"


            Hydrocarbons are from the fuel: gasoline is a hydrocarbon

            The nitrogen in the NOx comes from the air. Gasoline burning produces very little nitrate if any (nitrate = NO3-

            The only real contaminant is the sulfur. Car exhaust contains very little sulfur since the oil it was made from doesn't have much. Coal burning is another story.

            Eric

            P.S. Hey Rob: why not allow < sup > and < sub > in posts?

          • kind of like the question "where do hydrocarbons, sulfates, and nitrates come from when running my car?"


            Not at all like that. As edremy already pointed out, those products are all accounted for in the combustion of fuel.

            Incomplete combustion is nonsense: it doesn't form HF, as there is no hydrogen present in Teflon. Impure samples/contamination of oxygen supply: if this would be the case in any appreciable amount, then there still is no proper reaction path to form HF.

  • The simple ones.. (Score:4, Informative)

    by GoNINzo ( 32266 ) <GoNINzo.yahoo@com> on Thursday August 30, 2001 @06:34PM (#2237045) Journal
    Most of these are somewhat complex and some require like +3% solutions of acids/bases, which are difficult to get at best. In fact, some of these chemicals are 'call in the EPA if there is a spill'. But there are a lot of easy ones with materials that easy to get. Maybe they'll tune it a bit so they can list the ones you can do at home. I don't think I'm allowed to own 100% Hydrogen perxoide. `8r)

    As far as explosives go, lots of cool things to do with chemicals like magnesium and nitrates. Just might have to search a bit harder. `8r) But hell, just making hydrogen is fun, from electricity and water.

    • I see a "chemical experiments exchange" forum comming up on ./
    • Yup...witness this from the barking dog:

      "...exposure may cause little pain or go unnoticed, but the resulting edema several days later may cause death."
    • Actually, I think I remember seeing 99% hydrogen peroxide available at a drugstore.
      • Actually, it was probably more like 3% peroxide and 97% distilled water. 99% peroxide would eat your skin.
      • Actually, I think I remember seeing 99% hydrogen peroxide available at a drugstore.

        I really doubt it. 99% hydrogen peroxide (H2O2) is extremely reactive. It can be used as rocket fuel and will ignite on contact with anything organic. I believe it may even explode given a vigourous shake.

    • Although I don't pretend to know much beyond OSHA HAZWOPER taught me about chemical regulations, perhaps the reason for some of the more exotic/dangerous solutions might be that these people are based in Leeds, which is in the UK. From what I have been told by my British chemistry teacher Mom, regulations are a little more lax in the UK.
      • Yep. We've got security cameras all over our towns, but you can still go to your local ironmonger and buy DIY explosives.

        [handy hint: Sodium Chlorate weedkiller has a fire retardant in it, to stop it being used in explosives. Get it from the chemist instead.]
    • Has anybody tried the one where you explode common flour? You need a long tube and a candle. Suspend the tube over the candle, then gently sift the flour into the tube -- bang.

      Explosions are just supersonic burning. Many things will explode if divided finely enough and contained. I've heard that prisoners sometimes made pipe bombs out of playing cards by chewing and finely shredding them, stuffing them into a pipe. Obviously this takes time and motivation

      Uh -- does this mean slahsdot is going to be blocked by cyberpatrol?



  • finally proof of what goes on inside when you eat Cornflakes

    I always wanted to do this but was never allowed although I tried it with flower but got much worse results

    if you really like to blow things up custard powder rocks !

    this is why in medieval times they never allowed candles in the mill

    regards

    john jones
    • Pop tarts go up in flame *really* well. :)
    • nearly anything combustable, diveded finely enough and mixed in with a proper amount of air, will burn quickly enough once lit to pass for an explosive even though it may not meet whatever particular technical definition someone cares to point out. kaBOOM.

      An improvised m80 and a small bag of wheat flour can be used to demonstrate this effect in a wide open unpopulated area... and use a long fuse...

      Confine that reaction on a large scale, like in a grain silo; now you have Real Fun.

  • ... there are not captions, or explanation (theoretical or "proven") of how the chemical mechanism works! Unless it's so simple that it should be self-evident...

  • Invitation... (Score:5, Interesting)

    by don_carnage ( 145494 ) on Thursday August 30, 2001 @06:42PM (#2237080) Homepage
    Ok, is it just me or does the "don't try this at home" statement just make it all the more tempting.

    Not to plug my own site [dnsalias.com], but we have a really cool "fire in the bottle" [dnsalias.com] how-to video.

  • Let's post really obscure articles with absolutely no details, that way we can be sure the /. effect kicks in asap...

  • Physics Demos (Score:5, Informative)

    by dragons_flight ( 515217 ) on Thursday August 30, 2001 @06:55PM (#2237115) Homepage
    If you liked that, you might also want to check out the physics demonstration archive [umd.edu] at my old school (UMD [umd.edu]).

    IIRC It's the largest in the country.

    Oh yeah, the Question of the Week [umd.edu] is also very good.
    • I especially liked
      A1-51: SKATEBOARD

      PURPOSE: To do or to show whatever one wishes to do or to show with a skateboard.

      DESCRIPTION: Wooden platform with ball bearing wheels.

      SUGGESTIONS: If you use it, please let us know what you use it for.

      REFERENCES: (PIRA unavailable.) EQUIPMENT: Skateboard, as photographed. SETUP TIME: None.

      Nudge, nudge, say no more.

  • Best chemistry demonstation I've seen (Score:3, Interesting)

    by NonSequor ( 230139 ) on Thursday August 30, 2001 @07:09PM (#2237153) Journal
    The best chemistry demonstration I've seen was at the end of the year in AP chemistry. My teacher put magnesium filings in between two slabs of dry ice and lit them. So the magnesium was burning in carbon dioxide rather than oxygen. This produced an *extremely* bright light that lasted quite a while (much longer than magnesium in oxygen any way). After it was done we played with the dry ice (not many people were there since most of the people in the class were seniors and had graduation rehearsal that day).

    I also remember another demonstration in which he blew the lid of a can. I can't remember what he did then though.

    Great teacher, if it weren't for his preparation I wouldn't have been able to get a 5 on the AP Chemistry test.

    • I also remember another demonstration in which he blew the lid of a can. I can't remember what he did then though.

      Probably blew lycopodium into a can that had a lit candle in it. Classic experiment. Mr Wizard did this one on his show (he did a lot of stuff with lycopodium). You can get details from the site here [leeds.ac.uk].
    • basic subtext of your post: i got a 5 on ap chem when i wasn't even a sr!

    • My AP Chem class did soemthing similar...We put burning magnesium in water. The heat from the maghnesium ( ibleieve) spearated the O and H in the water, and the flame then burned under water on the generated H2. Pretty cool stuff.
    • The "silly chemistry trick" I remember best is an example of blowing the lid off of a paint can:

      Take standard paint can. Make small hole in center of lid, make another small hole in the side at the very bottom of the can. Use hose to pump the can full of that wonderful gas that all high-school chem labs are equipped with.

      Tell students that this is a nifty kind of implement by which one can read at night, and demonstrate by lighting the gas escaping via the uppermost hole.

      Set "camp night-light" aside, begin regularly scheduled lecture. Chuckle when the lid flies off of the paint can with a loud BANG and by some miracle lands in the trash receptacle by the classroom door.

      I don't remember a whole lot else from my high school chemistry classes (well, lots of discussions about moles... go figure) but that incident will remain vivid in my memory for many years to come.

      (Oh, and I'm assuming that I don't have to explain to you bright folks what made the BANG. Nope, didn't think so. Good.)

      --
      I am Grey. I stand between the water and the bread crumbs.

    • We have the pictures of this exact reaction on our web site. Check here [mattson] and here [mattson].
    • The demonstration you talk about is how I learned
      about lab safety in high school (the hard way).

      For my final demo in high school, I had bored a hole in a slab of dry ice (which is
      rather difficult to do) and placed some magnesium powder in it. My chemistry teacher also recommended that I mix in some potassium chlorate (strong oxidizer) in there.

      Well, I prepared the mixture, got another slab of dry ice to place over it, _held it down with my hand _(with the chemistry teacher watching), and lit the fuse.

      I should have noticed the evil smirk on the teachers face as I did this...

      What resulted was a little explosion right under my hand that broke the glassware on the bench and scared the daylights out of me. Luckily, the debris had spread out laterally, and I was not hurt.

      Other things I learned not to do by watching others in high school:

      -Do not stick your hand in forming polyurethane
      -Do NOT set up an experiment that produces gaseous copper
      -Phosphorus left in the sink will catch fire spontaneously in the middle of class
      -elemental sodium is not a toy

      Moral: always trust your own [hopefully paranoid] judgement about lab & on the job safety.

      Next time: how to alarm bedroom community with "improvised thermite" :)

      BTW, our textbook was Chemical Demonstrations [amazon.com] by Bassam Z. Shakhashiri.
  • Wait until they put up pictures of their web server exploding from the /. effect...

  • The Giant Artificial Poo [leeds.ac.uk]! Although if you have sulfuric acid in your digestive tract, you're more of a man then I am.

    • I don't think I'd want anything like that passing through my digestive tract. I always heard that feces were undigested fiber and dead bacteria. The "turd" in that experiment is just a piece of incinerated sugar. By the way, where is the professor's protective goggles and lab coat, and what about ventilation equipment? You can see the fumes rising from that black gunk.

      Roanna

      • What, that wasn't steam? :)

        I'm not entirely sure that the product is simply burned sugar. Obviously it trapped a lot of gasses along the way in order to increase in volume like that. But I wonder what the reaction was, and if you don't wind up with some kind of polymer instead? As far as I can tell, the text descriptions don't include this particular experiment.

        Yes, I know that this is not real feces. It's a joke, get it? Ha ha.

        I noticed the professor's lack of protective equipment too. Awful brave of him to be stirring a sulfuric acid solution so vigorously without so much as latex gloves on. But I guess that's why he's a professor and I'm just a geek.

      • Long ago I dated a chemistry grad student and he told me: "There are old chemists. There are organic chemists. There are no old organic chemists."

        Roanna

  • Random User writes: "No news on this site, just great photos of home-made explosions along with instructions on how to make home-made pipe bombs by yourself at home. Don't try this at home!"
  • There was supposed to be an earth-shattering kaboom?

    Uh, here it is, complete with instructions..

  • I was interested to see the "Barking Dog" reaction, because my high school chemistry teacher performed a chemical demonstration which produced a dog-bark sound. The reaction was different, though, and I'm wondering if anyone here has seen anything like this.

    What my teacher did was to dissolve white phosphorus in carbon bisulfide, soak a circle of filter paper in the solution, and lay the paper over the mouth of a large (maybe 1 liter) graduated cylinder. The carbon disulfide quickly evaporates, leaving a residue of phosphorus on the filter paper, which spontaneously ignites, sucking the air out of the graduated cylinder...and making a sound like the barking of a dog.

    hyacinthus.


  • OK, I skipped all the demos. I enjoyed chemistry but hated the labs. On the bottom of the page is a link to one of the web's most gorgeous periodic tables. Each group of elements is a different rainbow color.


    If you click on each element you see an image of it in nature and get its history. If you click on the chemical information you see its image in pure form.


    There are quicktime movies and Shockwave demos too. This is not the visual periodic table for nthing.



    Roanna

  • Reading over the experiments listed on the site reminded me of one experiment we did in honors high school chemistry which was NOT included. Our "teacher" was actually someone from the art department who was pressed into service as a chemistry instructor because he had a few chemistry classes in college. He walked in one day with a freaky, glazed look in his eye and announced to the class that we were going to be doing an experiment to start the day. He went into the back room, came back with a pair of tongs and bottle of kerosene containing a chunk of potassium metal, and gestured for us to join him outside. We gathered around a large rain puddle from the previous day's storm, and he asked what class was in the room next door -- English, as it turned out. Without any additional explanation, he reached into the bottle, grabbed the chunk of potassium with the tongs, flung it into the puddle, and stepped back. After a few seconds, the metal predictably exploded with a VERY loud bang, causing 35 English students to scream in unison and then rush to the window. The chemistry teacher stood there with a goofy grin on his face, and then shook his head and muttered to himself, "Yup...it's exothermic all right." (For those who read the article, he also did the thermite experiment during the year, but put about three times the recommended amount of magnesium in each student's setup. There were metal chunks in the ceiling tile for years afterwards...)
    • p>And then there was the time my high school chem class was doing the "what substances conduct electricity, in what states" experiment.

      Each pair was given three things to test -

      • water (tap water)
      • salt (NaCl)
      • octane

      We were to test each sample for conductivity at room temp and when heated.
      Most of us recognized the folly of putting octane in a 3mL crucible over a Bunsen burner.

      Not the pair of cheerleaders.

      Size of flame and diameter of scorch marks on the ceiling left as an exercise for the reader.

      Our science teacher really enjoyed the cheerleader's lack of common sense and excitability - he arranged a quiz, and lowered a pickled frog from a pulley in the ceiling to be sitting in front of their desk, at eye level while they were heads down working on the quiz... And the 'Miss Piggy and Kermit the frog' dance number with the fetal pig and pickled frog was a dramatic hit.

      Ah the joys of private school...

  • An interesting thing to note about chemistry demonstrations: Having participated in several demos at elementary schools, I've noticed that it doesn't matter what you blow up or set on fire, kids are always more impressed by do-it-yourself Gack/silly putty. Go figure.
  • ... Everytime he made an experiment it exploded.

    My favorite "kitchen experiment" is igniting a mix of flour and air to show that any powder being relatively explosive (very fun not to try at home)

    But the most violent explosion was mixing H2 and Cl2 and igniting with a laser beam (really NOT try at home, explodes at light exposure ;-)
  • Back in high school one of the home economics classes had people carry around flour or sugar "babies" (I think both were used). During that whole time I wanted nothing more than to find a forgotten sugar baby and dump sulfuric acid on it before returning it to the home econ department. I believe they would have considered the baby dead and failed whoever lost it.
  • I'm sure all slashdotters know how to make touch powder, but, just in case, I'm going to give the recipe:

    Add some iodine crystals to liquid ammonia (you just need the stuff that's dissolved in water). Filter and don't dry!

    I remember the time I made my biggest batch ever. About two tablespoons worth. It was family reunion and I put the stuff in blotting paper on my windowsill to remove excess liquid.

    I called my cousin, told him I've got something cool to show him. Took the paper, semi-dry now, walked through the crowded living room, went out the door. Shut the door, said, "This i..." and things got fuzzy here.

    Right, next thing I remember my hand was blue-purple, without feeling and I had this zinging noise in my head. He was staring at my hand like he's never going to see it again...

    So, the lessons here are:

    1. Never dry the stuff before you plant it!
    2. Never walk through a living room with thousands of elderly relatives that might suffer heart attacks with the stuff.
    3. Never put the stuff in blotting paper!
    4. Always remember, the purple stains are from iodine and evaporate within minutes.

    Well, have fun!

    "-and those damned stupid barbarians with their damned stupid swords will win after all..." -- Larry Niven (The Magic Goes Away)

  • I seem to remember a friend doing this [leeds.ac.uk] in Chem II class in high school, and getting detention for a week in the process.
  • Mr. Parker, I wonder if you (or your kids) read Slashdot...

    Oh, what glorious fun we had with thermite, with a VERY small bit of sodium in chlorine (yikes!), with deflagrated oxygen and red phosphorus.

    We never did get around to the filter-paper-soaked-with-perchlorate "land mines" that pop under your sneakers, but we *did* talk about it.

Slashdot Top Deals

The Tao is like a glob pattern: used but never used up. It is like the extern void: filled with infinite possibilities.

Close