xkcd

by **The-Rabid-Monkey** » Mon Jan 19, 2009 8:06 am UTC

flameburn wrote:I'd like to point out that thermite does NOT explode...it merely burns really, REALLY hot.

Let off a thermite reaction above water and the water explodes outwards due to it being super heated so quickly

by **Stripped Science** » Sat Feb 14, 2009 10:04 pm UTC

If you can get dry ice (CO2), just drop it inte water, and there will be some bubling and mist.

by **Khizrael** » Mon Feb 16, 2009 4:58 pm UTC

Let's not get too hi-tech here...

Heh. One of my favourite memories from my youngsterhood is asking my parents for a 'chemistry set' for my birthday. I used it to make things fizz and bubble for a while, then just let it disperse itself around the house. There were toxic chemicals knocking about for years. Lawd knows where they are now.

Also, vinegar and bicarb = massive win.

by **atimholt** » Tue Feb 17, 2009 9:54 am UTC

I was actually going to start a thread to describe the awesome thing me and my brother did, but this thread was here. Forgive me if someone has already posted the same thing.
I watched this video, and pretty much followed what it said. I'll quick describe it for those who have no time to watch videos.
We took a 2 liter soda bottle (draining it in a truly scientific fashion, with Mentos.), and cut off the top. Then we took a small water bottle, cut off the top and poked a bunch of holes in it. This we placed inside the larger bottle. We then surrounded the inner bottle with bits of dry ice to a high level. Finally, we poured in 91% rubbing alcohol (99% wasn't available at the grocery store we went to). When the alcohol stopped bubbling, we were left with viscous (cause of the 9% water), cryogenic rubbing alcohol!
The video describes it as "poor man's liquid nitrogen". The best part is all the stuff is available at a local grocery store. We shattered a rose and a couple other flowers, an orange (this we left in for a few minutes), and a reese's peanut butter cup (all the Valentines day candy at the store we went to is on sale, I've got at least 5 pounds). The guy in the video cautions that the stuff is unlike actual liquid nitrogen, in that it will not bead safely in your hand. It will instead spread and stick to you, a sort of "cryogenic napalm".
I really wanted to light it on fire afterward, but that was a lost cause from the start, as you might have guessed. I did get a little fog from dumping the sludge in puddles from the recent rain. This is certainly the coolest experiment I've ever done. It's just nearly 200 degrees hotter than liquid Nitrogen, is all. It still works.
We considered, briefly, also making a dry ice bomb, but the Wikipedia article effectively scared me away from that. I don't want to risk permanent hearing damage, I'm getting way into music right now in life. Nor permanent hand loss, that would suck.

EDIT: I don't think the guy in the video left his flowers in the stuff long enough. The rose we did shattered really well.

by **Poiesis** » Wed Feb 18, 2009 10:46 am UTC

Hmm...

Well, as a teenager I was quite fond of doing a simple acid/base extraction of the dissociative-anesthetic alkaloid in cough medicine, converting it to a more easily-metabolized citrate salt, and performing experiments in shamanism, parapsychology, ESP, astral projection, practical neuropharmacology and NMDA-antagonist psychotomimetics... all with spectacular results. But those days are behind me, and shall remain there barring unforseen necessity.

I am, however, looking forward to recreating a few of John C. Lilly's original sensory isolation tank experiments sometime in the near future.

These fora are amazing.

by **SWGlassPit** » Wed Feb 18, 2009 10:25 pm UTC

Robitripping, huh?

by **Cytoplasm** » Wed Feb 18, 2009 10:41 pm UTC

Has anyone tried celery in the microwave? It's fun to watch.

by **Poiesis** » Thu Feb 19, 2009 2:18 am UTC

SWGlassPit wrote:Robitripping, huh?

It really is fascinating! I even once used it to successfully reverse an acquaintance's daily heroin addiction (never went there myself, thankfully), preventing him several days of hellish withdrawal syndrome with a single administration. There's lots of fascinating and conclusive research into the high efficacy of NMDA-antagonists in treating opiate dependence by resetting opioid receptors. But I digress.

Cytoplasm wrote:Has anyone tried celery in the microwave? It's fun to watch.

Nope. *Makes note.*

Though, if you take a grape and cut it nearly all the way in half (but leave some skin holding the two halves together) and put it flat-sides down on a plate and microwave for 10-15 seconds you get some neat sparks

by **Cytoplasm** » Fri Feb 20, 2009 2:56 am UTC

Poiesis wrote:
Though, if you take a grape and cut it nearly all the way in half (but leave some skin holding the two halves together) and put it flat-sides down on a plate and microwave for 10-15 seconds you get some neat sparks

Oh goodness! I will have to make a note of this also! Thanks!

by **Poiesis** » Fri Feb 20, 2009 8:20 am UTC

Cytoplasm wrote:
Poiesis wrote:
Though, if you take a grape and cut it nearly all the way in half (but leave some skin holding the two halves together) and put it flat-sides down on a plate and microwave for 10-15 seconds you get some neat sparks

Oh goodness! I will have to make a note of this also! Thanks!

My pleasure! Please inform of your subsequent results!

by **wst** » Sun Feb 22, 2009 1:16 pm UTC

Marshmallows in the microwave. Do eet!

by **Gojoe** » Sun Feb 22, 2009 1:18 pm UTC

wst wrote:Marshmallows in the microwave. Do eet!

HELL YES! I love this!

Spoiler:

by **The-Rabid-Monkey** » Mon Feb 23, 2009 5:07 am UTC

So... Any new ideas that haven't been repeated over and over again?

by **Wildcard** » Mon Feb 23, 2009 8:30 am UTC

Cytoplasm wrote:Has anyone tried celery in the microwave? It's fun to watch.

What happens when you do it?

Is it damaging at all to the microwave (or to the cleanliness of the microwave)? Can you eat the celery afterwards?

If the answers are no, no and yes, then I'll try it myself.

And, not an experiment in the sense of most of these, but a fun home project (for kids, which is the original, ancient idea behind this thread) is to make a home made Jacob's ladder. Fascinating things. For bonus points you could make a 2 dimensional one, ala Rubik's Magic.

by **atimholt** » Tue Feb 24, 2009 9:55 am UTC

Does anyone know of a way to consistently superheat water in the microwave, or wherever ? Please also provide appropriate safety precautions and fun things to do with superheated water. What happens if you mix it with cryogenic rubbing alcohol?
Also, what the friq? apparently the correct spelling for 'wherever' is 'wherever,' which is how I spelled it the first time. You'd think it might be 'where ever' or 'whereever.' On second thought, no you wouldn't.

by **J Spade** » Thu Feb 26, 2009 12:48 am UTC

Superheating water only requires a strong, airtight container that can handle high temperatures. If it doesn't boil, it will keep getting hotter after 100ºC. After that, the safety is to treat it like hot stuff, cuz' it is, and steam burns suck. Use oven mitts/tongs and keep away from face.

EDIT: I've never done it because I never really decided to, so if I missed something let me know.

by **The-Rabid-Monkey** » Thu Feb 26, 2009 2:07 am UTC

Also, a note on super heated water. Don't add impurities, it goes BOOF.
Aka, don't use it to make yourself a coffee.

by **eternauta3k** » Thu Feb 26, 2009 3:11 pm UTC

J Spade wrote:Superheating water only requires a strong, airtight container that can handle high temperatures. If it doesn't boil, it will keep getting hotter after 100ºBASIC. After that, the safety is to treat it like hot stuff, cuz' it is, and steam burns suck. Use oven mitts/tongs and keep away from face.

OOPS: I've never done it because I never really decided to, so if I missed something let me know.

I'm not sure increasing the pressure and then heating counts as superheating. He has to raise the vapor pressure of the water over the container (or atmosphere)'s pressure. AFAIK, It'd take reasonably pure water, a scratch-free container and avoid movements/vibrations. Also, it might boil and blow up in your face.

by **SWGlassPit** » Thu Feb 26, 2009 7:21 pm UTC

Yeah, increasing the pressure simply increases the boiling point. It doesn't enable you to raise the temperature of liquid water past its boiling point. Basically, when water boils, those little steam bubbles need a nucleation site--something to attach to in order to form. If you use a very smooth glass container, it is possible to heat the water higher than the boiling point because there is no disturbance in the water that allows these gas bubbles to form. Even the slightest bump, however, will cause superheated water to instaboil, which can be a Very Bad Thing.

by **Dimetrodon** » Tue Mar 03, 2009 2:56 am UTC

SWGlassPit: Excellent! Thank you! I had never understood the science behind that before.

Has anyone here experimented with Fresnel lens? Apparently you can use the large ones from big tv's to melt pennies, although I've only been able to light paper on fire with mine.
Also, I'll be making my own bismuth crystals on a stove sometime, maybe within the week. Has anyone done this before? Any tips?

by **breintje** » Wed Mar 04, 2009 6:33 pm UTC

Dimetrodon wrote:Has anyone here experimented with Fresnel lens? Apparently you can use the large ones from big tv's to melt pennies, although I've only been able to light paper on fire with mine.

I set fire to some medium sized sticks using a fresnell lens. It did go out however when you moved the lens away, but I guess with some tinder it would go up easily. Have to try the penny thing once. Or put a negative lens at the focal point to create a nice beam. This lens, by the way, was the size of an A4 paper sheet and was used to increase yield from some solar panels in a school contest, allowing me to charge ~6.5V at 100 mA from 2 1V 450 mA and 1 1V 300mA (peak) solar cells. Obviously the PBC lowered the efficiency, still it was more efficient then putting them in series to charge 2.4V batteries. What I noticed when I put the thing outside the day after the race is that this power only lasts some 10-15 minutes, then the cells heat up and output halves.

by **Destructonaught** » Thu Mar 05, 2009 11:19 am UTC

I'm surprised... I haven't yet seen a single reference to chlorine/alcohol reactions (I may be mistaken, so don't flame me if I am

)

Essentially it works the same way as the well documented dry ice and water technique. Add alcohol to (as a personal preference) chlorine pellets in a coke bottle or something. Put the cap back on the bottle. Like the dry ice/water reaction, the alcohol and chlorine will react (I'm unclear on the exact details as to how) but suffice to say it produces a gas and BOOM.

I've seen a video (and most of you probably have as well) of some pre-teen looking guy with his mates putting alcohol and chlorine together. Only he decided to put the cap on and shake the bottle. It exploded in his hand.

I laughed. Considerably.

by **oxoiron** » Thu Mar 05, 2009 3:39 pm UTC

What are chlorine pellets and where would one get them?

by **Destructonaught** » Thu Mar 05, 2009 9:03 pm UTC

they're reasonably obtainable, as far as I know. You can buy them at one of those el-cheapo stores (for myself it would be Big W, K-Mart or similar). They are sold in 1kg tubs of pellets for chlorinating backyard pools.

by **oxoiron** » Thu Mar 05, 2009 10:00 pm UTC

Gotcha. So they aren't really chlorine. They are a mix of NaOCl and Ca(OCl)₂.

by **The-Rabid-Monkey** » Fri Mar 06, 2009 4:25 am UTC

Dimetrodon wrote:Has anyone here experimented with Fresnel lens? Apparently you can use the large ones from big tv's to melt pennies, although I've only been able to light paper on fire with mine.

I've been wanting to get a rear-projection TV so that I can extract the lens and whack it into a frame. I've seen videos of a guy with a 60inch one or something, melting a large hunk of iron. It even started to boil after a while. Quite warm.

by **Destructonaught** » Fri Mar 06, 2009 5:19 am UTC

oxoiron wrote:Gotcha. So they aren't really chlorine. They are a mix of NaOCl and Ca(OCl)₂.

ugh. Sorry, I'd forgotten about that... I'd used chlorine pellets in an alcohol bomb mix before so I just figured they would work the same. Would those pellets still work? (Newbie alert...)

by **oxoiron** » Fri Mar 06, 2009 3:11 pm UTC

I wasn't so worried about whether the reaction would work, I was just trying to figure out what you meant by 'chlorine pellets'. I think we can all agree that when giving and receiving instructions on mixing chemicals, it's usually a good thing if everyone is on the same page.

by **gavinski91** » Fri Mar 06, 2009 11:40 pm UTC

i dunno if this ones been mentioned yet, but its really cool...
supplies: Drain-O crystals, water, aluminum foil, flask (i used a 1000 ml pyrex flask, but apparently a gatorade bottle works too) and a balloon

put about 1 inch of water in the bottom of the container, and drop in a bunch of aluminum.
then pour in a bunch of draino crystals, and cover the neck of the flask with the balloon.
heres the reaction... 2NaOH + 2Al = H2 + 2Na + 2AlO
thn, of course, it follows that: 2Na + 2H2O = 2NaOH + H2
and i just keeps goin in a circle until u run out of aluminum...
and ur balloon fills up very quickly with hydrogen, so you can tie the balloon shut, clamp it down, and hold a lighter underneath it...
of course, prepare to lose some arm hair in the process..
if ur flask has a long neck, you can also send balls of flame shootin down it into the flask by igniting a lighter above the flask...
and of course, be careful, cuz this shit's dangerous.

also, if ur into big booms, heres a good story..
a bunch of my friends and i were at the beach, and we had a charcoal fire goin in a grill, and some russians went to the picnic table next to us and started a wood fire... which meant bigger flames, so we got one-upped... (call me mario... ) so we started usin lighter fluid...
after a while, we waited til our charcoal had no flame... and my friend stood 5 feet back and started spraying lighter fluid into the grill... after bout 30 seconds of spraying i threw a match from the same distance into the grill (took me two attempts)...
who needs to wax their eyebrows anyways? and my friend, whos hair is dead straight, actually had a bunch of curls on the front of his head... figure the resulting ball of flame had a diameter of 8 feet..

anyways, for tons of cool stuff to blow up:
http://home.scarlet.be/comicstrip/anarcook/indanarcook.html

by **oxoiron** » Sun Mar 08, 2009 4:38 am UTC

gavinski91 wrote:heres the reaction... 2NaOH + 2Al = H2 + 2Na + 2AlO

Are you trying to say that Al_(s) will reduce Na⁺_(aq) and after also reducing H⁺, you end up with Al²⁺?

Methinks there may be something wrong with that reaction as written.

by **rowena** » Sun Mar 08, 2009 7:43 am UTC

This is probably not a safe home experiment unless you're my science teacher...
Or someone equally as skilled in not electrocuting themselves.
But if you get a pickle, and attach both ends to forks and attach the forks to metal poles (make sure everything else surrounding is an insulator) and attach alligator clips to both forks and carefully plug straight into the wall,
this creates a rather bad smelling but entertaining 'pickle light bulb' that oozes black water but is rather bright. Note that often before anything happens the pickle will begin smoking at one end.
I'm glad I asked my science teacher why he kept a jar of pickles next to bottles of interesting chemicals (acids, sulfate etc) at the back of the room.
Excuse punctuation and/or grammar, I write at thought speed.
Enjoy!

by **The-Rabid-Monkey** » Sun Mar 08, 2009 11:16 am UTC

rowena wrote:stuff about pickles

This works with Plums to, and presumably apples and oranges etc to.

http://www.youtube.com/watch?v=ogX74kPse4Y - me being a cock

by **rowena** » Mon Mar 09, 2009 5:01 am UTC

Heh, what ingenuity.
The problem you were having with the nails melting through the pickle and falling out can generally be solved by using forks (as larger surface area and more jamming potential)
Yeah, probably not safe for most people, particularly ones unfamiliar with the equation 'A lot of electricity + human = carbon + oh gosh darn I'm dead'

by **gavinski91** » Tue Mar 10, 2009 10:27 pm UTC

oxoiron wrote:
gavinski91 wrote:heres the reaction... 2NaOH + 2Al = H2 + 2Na + 2AlO
Are you trying to say that Al_(s) will reduce Na⁺_(aq) and after also reducing H⁺, you end up with Al²⁺?

Methinks there may be something wrong with that reaction as written.

ummmmmmmm....
wht ur sayin doesn't really make sense related to how you quoted me, since i'm converting aqueous sodium hydroxide, not sodium..
i'm not seeing any problems with it written how it was.
2NaOH + 2Al = H2 + 2Na + 2AlO

by **gavinski91** » Wed Mar 11, 2009 12:00 am UTC

Meteorswarm wrote:
gavinski91 wrote:
oxoiron wrote:
gavinski91 wrote:heres the reaction... 2NaOH + 2Al = H2 + 2Na + 2AlO
Are you trying to say that Al_(s) will reduce Na⁺_(aq) and after also reducing H⁺, you end up with Al²⁺?

Methinks there may be something wrong with that reaction as written.

ummmmmmmm....
wht ur sayin doesn't really make sense related to how you quoted me, since i'm converting aqueous sodium hydroxide, not sodium..
i'm not seeing any problems with it written how it was.
2NaOH + 2Al = H2 + 2Na + 2AlO

His complaint is that +2 is not a stable oxidation state for aluminum, so writing AlO rings a lot of warning bells. It's forming Al₂O₃.

Interestingly, Al₂O₃ is acid-basealicious, I mean, amphoteric.

ya i'm an idiot... my bad for being lazy and guessing at oxidation numbers that i should know anyways.

by **oxoiron** » Wed Mar 11, 2009 2:44 pm UTC

I was also saying you can't reduce sodium with aluminum, something you implied by writing your reaction with non-ionic sodium as a product. :wink:

by **pauliswhoiam** » Sun Mar 15, 2009 6:17 am UTC

I think the hydrogen one is a really fun one.
I've never tried the bubble method, but I've made a decent pop in a milk jug.
Does adding salt really make it produce chlorine gas? I only used very small quantities so I guess that would explain my lack of melting lung tissues. I'm not sure it'd be that easy to produce WW1 like quantities by this method.
I never tried hooking my electrolytic container to a larger receptacle, but I'm sure it only takes a few logical steps to recreating the hindenburg.

On another note, try mixing pure tones from two different speakers to get cool interference effects. There's a thing you can do with headphones and this method which truly messes with your brain, I have no idea how it works, I'd love someone to explain it.
Or if you have a prism and can make slits in pieces of paper, you can produce lovely interference patterns with light, and hence measure it's wavelength.
Also, a NSFW pharmacology experiment; coldwater extraction of codeine from codeine+paracetamol mixed tablets. These are available over the counter in the UK and codeine is a very pleasant mild opiate.

by **wst** » Sun Mar 15, 2009 6:35 pm UTC

pauliswhoiam wrote:available over the counter in the UK and codeine is a very pleasant mild opiate.

Uh, 12.8mg of codeine to 500mg paracetamol... or prescription. It's really not worth it. It's cheaper to buy opium poppies

by **ducksan** » Sat Mar 28, 2009 1:03 am UTC

A few miscellaneous comments. Hydrogen production from lye and aluminum proceeds first by the dissolution of aluminum oxide by hydroxide, then the hydroxide attacking the aluminum metal itself. The product is a compound I don't know much about, sodium aluminate (Na₃AlO₃) and hydrogen. Tie the balloon to a string and light it with a candle on a stick for maximum not burning yourself-age.
Aluminum does react with water once you scrape off the oxide, but lye speeds up the hydrogen production considerably.

Also, chlorine-alcohol can indeed make chlorine gas. Beware. I had no idea what was going on here before I took organic chemistry, and the mechanism of oxidation by chlorine and OCl^-/HOCl is still unclear to me.
All sorts of chlorinated compounds can be made, to the best of my knowledge, even chloroform by the haloform reaction. iPrOH is usually taken to the ketone acetone, unless you cut it up or chlorinate it further.

I once mixed isopropyl alcohol with calcium hypochlorite, expecting a hypergolic reaction. Upon ignition, the alcohol burned with a normal flame, essentially oblivious to the oxidizer I added. However, the alcohol was a gel before I added the hypochlorite, and I found that the Ca(OCl)₂ not only destroyed the gelling agent, but the red color. Later, I added a few hypochlorite granules to a sample of the alcohol gel, hoping to prepare liquid alcohol. That's when it turned a bit yellow and began reeking of a pool. This was surely chlorine, and I tossed the sample in the fireplace and torched it before anything else could happen.

I theoretically designed a rig to make chlorine from HCl and Ca(OCl)₂, cool it to a liquid with dry ice, and react it directly with copper to make copper(II) chloride. The stuff is a neat flame color agent, isn't too cheap to buy, and I could theoretically save money by making it myself. (The metal does not dissolve well in hydrochloric acid.) Ignoring the gross safety issues, most of my ideas don't make it off the drawing board anyways, including this one.

by **dhokarena56** » Sat Mar 28, 2009 11:40 pm UTC

Neither of these have I tried, but I think they'll work. So, I take no responsibility if something bad happens.
1. Ever had trouble getting a hairspray spud gun to work? Have no fear!
First, take a fairly long pipe, and an "end". Cement the end onto the pipe-now there's only one opening.
Throw in some dry ice crystals. Pour in some water, and very quickly ram a spud down the barrel. Enjoy!
2. This isn't an explosion-it's a prank. Buy a heck of a lot of clear, no-flavor gelatin. Dump it all into a toilet bowl, around 11 or 12 at night. Add ice cubes Now-every 1-2 hours, put in more ice cubes... if all goes well, you will have a jello toilet bowl in the morning.
However, it would be unflushable, and disposal would be hard.

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