[hopeful]

Ok, so my teacher briefly touched on colloids in class and then gave a demonstration on them. She mixed something with some alcohol (I know, I'm just to specific arnt I) and it formed kind of a slush that she could form into a ball with her hands. She than proceeded to light this on fire. The best part about her demonstration is that you could hold the flaming ball simply by first dipping your hands in water. She refused to tell us the formula saying that while she would like to, it is against school policy to do so. This has really been urching me, seeing as I feel that i am a fairly decent chemistry student, my only problem is that i cannot find enough information on colloids in order to figure this out. If someone could please please please just help me learn about colloids, and/or if you know the formula divulge it that would save me nights of sleep.

Thank you so much, and i promise not to use this to do harm, this experiment just greatly intrigues me.

Eric Lasker

[mike]

Which part intrigues you? The fact that she made some kind of slime or the fact that you could light it on fire?

Making slime is quite easy to find the procedure for. However the only reason that it would light on fire is due to the alcohol in my opinion. Also I would NOT recommend light any solvent on fire while it is contact with your skin, there are MANY reasons why this could go terribly wrong, ie. different solvent sburn at different temperatures so if you use the wrong one you are going to be sorry, some solvents are not water soluble so if you light it on your skin and can't wash it off with water what are you going to do? Solvents often tend to "flash-back" so simply by lighting the solvent on your hand you run the risk of igniting vapour in the air or worse still the whole bottle. For some reason when people light things on their hand, on becoming too hot, they tend to hold their hand against their body, thus burning themselve even worse than before. Dipping your hand in water before lighting the ball on your hand will only work for a short period of time and may depend on the solvent and the quantity.

In my opinion the demonstration was irresponsible, more so than giving you the procedure for the reaction. I think your teacher has has her priorities very wrong.

My advice is go ahead and investigate colloids and polymers by all means BUT keep flames away from such experiments and NEVER light your self on fire deliberately (your teacher should know better than that!)

[enahs]

In my opinion the demonstration was irresponsible, more so than giving you the procedure for the reaction. I think your teacher has has her priorities very wrong.

Ehh, I never would have gotten interested in chemistry if I did not have somebody show me things I could do that where dangerous and could cause serious bodily harm. I bet you will find a larger percentage of chemist will say the same thing!

[mike]

Ehh, I never would have gotten interested in chemistry if I did not have somebody show me things I could do that where dangerous and could cause serious bodily harm. I bet you will find a larger percentage of chemist will say the same thing!

I bet you that they wouldn't 

These are not really the type of people I want becoming chemists in the first place, sorry.

[lavoisier]

It's only fair to admit that 'danger' has some kind of perverse fascination, and I believe quite some people got interested in chemistry because of the powerful nature of the forces one is able to master, or by the seemingly mysterious behaviour of some systems...

Having said that, it's clear that nobody can seriously become a chemist without making a big step forward.
I mean that one is allowed to be childishly attracted by flames and colours at the very first stages of his interest in chemistry. After that, a serious study of the properties and behaviour of matter must follow, and one should appreciate the beauty of the order and regularity we find in nature. Otherwise one would better go and see magicians shows forever.

From a practial point of view, it's right because one's called to deal with potentially dangerous systems, that he needs a rigorous, safety-conscious, scientific approach.

Nobody with a bit of brain would endanger himself for no reason, even less so when he doesn't know what he's doing.
When you are a professional chemist, and you NEED to use hazardous substances and methods, I assure you that you take all possible precautions against 'bodily harm', which is no fun at all.

[mike]

Flames, explosions etc are all well and good until something goes wrong and a student's parents decide that they are going to sue the teacher, suddenly then it is not so easy to explain away the lack of safety precautions. Sure a spectacular and dangerous show may spark an interest in chemistry for some students, however one really bad accident (some have been talked about on this forum already, including very badly burnt students) is enough to turn off just as many parents and students from chemistry.

You guys say that people get into chemistry because of the danger and ability to cause serious bodily harm? To me this sounds like someone who enjoys car crashes so becomes a race driver, or someone who enjoys sickness and death becoming a doctor. plane crash = pilot, animal cruelty = vet, pyromaniac = firefighter. There is no doubt some element of truth here but it doesn't sit right with me.

Deliberately lighting a flammable solvent while it is on your skin is particularly dangerous (even as far as dangerous demonstrations go). You know that sticking a fork in an electrical socket could shock you, you don't have to do it to prove it to yourself.

[Borek]

one really bad accident (some have been talked about on this forum already, including very badly burnt students)

http://www.chemicalforums.com/index.php?topic=6587.0

[enahs]

You guys say that people get into chemistry because of the danger and ability to cause serious bodily harm?

Fire and explosions and such are exciting. Most people when they are young are only interested in things that excite them, or what they are told to be interested in.

I mean, think back to when you where 13. If two people came to your class and gave a demonstration, which of the following would most likely interest you in studying science?

Person A shows you how to balance a equation on the board and person B submerges a flower in liquid nitrogen then drops it and it shatters. Which one is more interesting and will get your attention and excitement?

It does not have to cause bodily harm, but something has to excite you to get you interested (in some form). It could be just excitement about building a rocket ship to go to the moon, anything.

I also understand your desire to want to be safe, especially when you are risking somebody else's safety and not just your own. But one of the whole points of science is to understand things, and if you are careful and understand things you can handle and do dangerous things very safe. If this is not the case, then you have no business in a chemistry lab because you can hurt your self badly with even a mild acid. But to say you should never do something dangerous is just ridiculous, as inherently so many things we need to do to further our understanding in science will be dangerous.

[mike]

I agree with you that young students (primary and high school) are interested in exciting things.

And I agree that if someone goes to a school, that visually stimulating demos are better than theory and board work. Sure, liq N₂ is great as are luminol, foam, colour changes, solar cells, smoke etc. Now these demos are relatively safer than demos involving fire or explosions which are more inherently potential hazards, to start with.

One problem with spectacular demos used to interest students in science is that invariably the demos have very little to do with the type of study or work that will come to follow at higher levels, so this is something to keep in mind. The promotion of science should be somewhat more balanced than just a "magic show". If the audience has no intention of becoming scientists then sure a bit of light entertainment is fine.

Second, you can see right here in this thread exactly what happens when "playing with fire". A students has seen a teacher light their hand on fire and it looked spectacular. Now this student hasn't gone out to become a scientist, they have jumped straight on the internet to try and find out how to set themselves or their friends on fire in the same manner, no doubt in a much less controlled and much less safe environment (I doubt they are going to do it in a proper lab, with good ventilation, fire extinguishers, fire blankets, sand, high pressure water, trained chemists and first aid staff and quick access to emergency services if required.).

I am not sure how old the posters are here, but you would have to be a little naive to presume that young students won't try and copy cat dangerous stunts.

By all means use flashy demos to interest students in chemistry. My point is more don't set yourself on fire, don't ignite acccelarants, don't explode things, there are plenty of other ways to get peoples attention, and if you can't get their attention without these dangerous things, then maybe they shouldn't be encouraged to be chemists in the first place. Injuries from chemicals are often really awful (burns, poisoning, blindness etc.)

Be careful, leave the experiments to your teacher or lecturer, DON'T TRY THIS AT HOME.

[hopeful]

I now see the juvenile nature of my question and I apologize, I hope that this one request does not taint my record on these boards as I hope to use these boards as a supplement to my self taught knowledge (seeing as I have exhausted the one chemistry class offered by my school).

Thank you, I see my fallacy
 

[constant thinker]

Lighting yourself on fire...

It's not as fun and cool as it sounds or looks. It hurts, and the pain lasts for weeks sometimes.

I hate it when people are irresponsible. Someone was ill informed that concentrated acetic acid is not like vinegar. They wound up squezing a pipette full of it, and hitting someone in the face. The person fine because he had goggles on, and the teacher was right there to react to the situation. He does have a mark across his forehead though.

My point here is, chemistry can yield some pretty interesting and cool demonstrations, but you need to take care and precaution. This teacher didn't. They blatantly told the students what she used. Someone who isn't as well educated in what can happen and safety precautions can easily go home and try it. Then that person can get hurt, seriously sometimes.

[mike]

I now see the juvenile nature of my question and I apologize, I hope that this one request does not taint my record on these boards as I hope to use these boards as a supplement to my self taught knowledge (seeing as I have exhausted the one chemistry class offered by my school).

Thank you, I see my fallacy
 

I am sorry I wasn't having a go at you personally, I really meant students in general. The main point is to be careful and to not hurt yourself or others. You are more than welcome to use these boards and I hope they are helpful to you.

Back to your original question; I did actually allude to a way to find out more information about this demonstration when I said that making slime is easy. I imagine that the compound was what is commonly used as "slime" in lab demos. I am more than happy for you to find out about the chemistry behind slime, I just don't want people hurt. So maybe go and investigate slime and then come back to the board and I am sure there will be loads of people happy to answer your questions about it.

Don't let me put you off

Good luck, mike