Boom!

[MrB (Simon)]

Berrie, I have read that the rooftop cameraman did not survive.
22 or 23 deaths(different sources)
900+ injured
1,200+ homeless

[bloodhound31]

Originally Posted by Baddad

Hi Baz,

Oxygen does not burn. It combines with whatever is burning, like hydrogen, carbon or iron. That is to be correct in chemistry terms.
We also use burnt carbon (CO2) to extinguish fires. Carbon is the main ingredient in gunpowder.

Cheers Marty

Although it was tongue in cheek and I understand that the combination of Hydrogen and Oxygen dramatically changes things, I'll be the first to put my hand up and admit my basic knowledge of chemistry sucks.

Will things burn without oxygen? So far I have been taught that if you starve a fire of oxygen, it will go out.....

Baz.

[AstralTraveller (David)]

That is true of fires you normally see. Fire is an example of an oxidation reaction but oxigen is not the only oxidizing agent. In a redox reaction the oxidizing agent is any species that can accept electrons - and the reducing agent is one that donates electrons (confusing terminology isn't it). So element such as chlorine and fluorine can also be oxidizing agents.

Also the oxidizing agent doesn't have to be present as a gas. In APCP the ammonium perchlorate (NH4ClO4) is the oxygen donor and some metal (typically aluminium) is the reducing agent. APCP has the advantage that while donating oxygen it decomposes to yield nitrogen gas (amongst other things) thus increasing the volume of the material dramatically and so adding to the thrust.

[marki]

Yep there's lots of different oxidising agents besides oxygen itself. One of the demo's I do with my chem students to illustrate this is to bubble chlorine gas through a large measuring cylinder full of water. If you drop calcium carbide in to the water it reacts to form acetylene gas which then reacts with the chlorine gas and burns. It's pretty cool as the gases ignite under water and looks a bit like fireworks. Best of all it allows the students to see fire in an enviroment they would not have thought possible.

Mark

[AstralTraveller (David)]

Originally Posted by marki

Yep there's lots of different oxidising agents besides oxygen itself. One of the demo's I do with my chem students to illustrate this is to bubble chlorine gas through a large measuring cylinder full of water. If you drop calcium carbide in to the water it reacts to form acetylene gas which then reacts with the chlorine gas and burns. It's pretty cool as the gases ignite under water and looks a bit like fireworks. Best of all it allows the students to see fire in an enviroment they would not have thought possible.

Mark

Are you a high school teacher? That sounds a pretty full-on demo for high school. I didn't know anything so 'interesting' was allowed. You must need a fume hood at least.

[marki]

Originally Posted by AstralTraveller

Are you a high school teacher? That sounds a pretty full-on demo for high school. I didn't know anything so 'interesting' was allowed. You must need a fume hood at least.

Yes. the fume hood is a given even though I can name a few students who would benfit from a good sniff of Cl2 . The reaction is actually quite gentle as the Cl2 is made by mixing HCl with KMnO4 so production of the gas is slow (no heat). I also do one with I2 crystals, Al and water. This is great, lots of red flame and purple smoke (yes in the fume hood ) but it does get very hot (i.e. melts the sand bed). I also do the thermite reaction (mix and run away ) on the back oval as well as several others. The do gooders have not killed chemistry entirely yet and the kids love it as it gets them out of yet another boring theory lesson. I think they really enjoy watching me sprint away from impending doom as well .

Mark

[MrB (Simon)]

Wish my high-school science teachers were as interested in their students as you obviously are.

[Jen]

Originally Posted by MrB

Wish my high-school science teachers were as interested in their students as you obviously are.

i was gonna say the same thing me too. i would have been a straight A+ student if Mark were my teacher

[TrevorW]

I used to mix condies crystals and glycerene as a kid. Made nitro and gunpowder, flash powder etc all the chemicals could be purchased over the counter even done the old acetylene trick as well

[marki]

Originally Posted by TrevorW

I used to mix condies crystals and glycerene as a kid. Made nitro and gunpowder, flash powder etc all the chemicals could be purchased over the counter even done the old acetylene trick as well

Trevor, I used to do one with acetylene in a volumetric flask. Basically fill it up and set it on fire . It burns down very slowly but one day I had a mishap and the bloody thing turned into ramjet then exploded. Lucky I had the protective shield over the top or all hell would have broken lose (pyrex shards cut deep). We also do a similar thing with H2 gas in a milo tin with a hole in the top. This one is a little unpredictable (run away ). Touch powder, solid rocket fuels, smoke bombs etc are lots of fun as well.

Jen I don't know how I would have delt with all of your assignments and tests written in purple and there are no extra marks for emoticons . Crikey I have just finished marking 70 odd exams and my eyes are dead.

Simon, I love science especially chemistry and that does rub off on the kids ( I am extremely enthusiastic). Since I have been at my school, the number of students taking chemistry and physics has doubled which is bucking the national trend for these subjects. This year we enrolled 50 students in year 11 chem (25% of the year group) and I have another 25 in my year 12 class. If you have a passion for what you teach the kids can see it and want to become involved. I get such a buzz watching their minds develop as well as their desire to learn more and we do have a lot of fun along the way.



Mark

[BerrieK]

Originally Posted by marki

Touch powder, solid rocket fuels, smoke bombs etc are lots of fun as well.


I get such a buzz watching their minds develop as well as their desire to learn more and we do have a lot of fun along the way.

Mark

LOL an old flatmate of mine was a jeweller who liked to dabble in chemistry....he used to make all sorts of stuff in the shed. One of his favorites was touch powder.....he used to put it on the toilet (very naughty boy) and wait for the scream (no bums were injured somehow, or not that I remember or will admit) or if I had had a particularly outragous night the next morning he would put it randomly along the bannister of the stairs in our grotty little inner Sydney terrace.

Mark you sound like my old chemistry teacher from years 11 and 12 high (only a few years ago of course haha) who was exuberantly enthusiastic....his classes often involved either the fume hood or being outdoors and being ready to run. It was great. My dad was science master at another school and reports had it that his classes were aslo highly entertaining.

Mark your students are really lucky to have an enthusiastic, passionate teacher who is genuinely interested in their field.

Aah, the good old days... thanks for bringing back those memories...

Kerrie

[AstralTraveller (David)]

I was asking because I've never seen a fume hood in a school. Where I went the most exotic piece of equipment was a bell in a vacuum chamber (to demonstrate that sound doesn't travel in a vacuum) and I think the most spectacular demo was Na in water or burning Mg. The teacher was pretty good but hamstrung by a lack of resources. (We had to make touch powder ourselves .)

On the other hand my boss went to an exclusive North Shore school and had his own petrographic microscope. I'm not bitter (and know that others didn't even get the chances I had) and wouldn't be him for quids but so much for equal opportunity.

[BerrieK]

Originally Posted by AstralTraveller

I was asking because I've never seen a fume hood in a school. Where I went the most exotic piece of equipment was a bell in a vacuum chamber (to demonstrate that sound doesn't travel in a vacuum) and I think the most spectacular demo was Na in water or burning Mg. The teacher was pretty good but hamstrung by a lack of resources. (We had to make touch powder ourselves .)

On the other hand my boss went to an exclusive North Shore school and had his own petrographic microscope. I'm not bitter (and know that others didn't even get the chances I had) and wouldn't be him for quids but so much for equal opportunity.

I went to a public high school in a country town with a population of just approx.12000 (back then it was about 9000).

I think that sometimes the presence of 'exotic' gucci gear in a school lab is related to the enthusiasm and push of the teachers - not always just related to the financial situation of the school. Enthusiastic teacher = campaigning for cool stuff by teacher on behalf of students, and depending on the available resources (monetary or otherwise) of the school and the submisison writing skills or powers of persuasion of the teacher / s, the gucci gear becomes available.

Another factor is what is 'standard' for a school to have at the time. For example my dad tells me that when I was at school many public high school in NSW were issued with a reflector telescope on a basic eq mount.

Kerrie

[marki]

Originally Posted by AstralTraveller

I was asking because I've never seen a fume hood in a school.

All of the WA high schools I have worked in (both public and private) have had at least 1 fume hood but more usually 2, one in the techs prep room and one in a dedicated chem lab. In fact the last public school I worked at was well designed with two fume hoods in the techs prep room each backing onto seperate classrooms. They had double sided access so no one was ever waiting to use them. I am not sure how it is done in other states but you could not complete the upper school chemistry curriculum over here without a fume hood as many of the pracs involve nasties that could not be used. In year 11 they must know how to make Cl2, SO2, H2S, NO2 etc. With the 12's we use a lot of organics, toluene etc so they are a must have item.

Mark

[Baddad (Marty)]

Hi Mark,

I'm reluctant to confess what I used to get up to in school. I was the top chem student and the Lab assistant was a close personal friend of mine. I learnt a lot very quickly. Youthful exuberance motivated me.

I never dared to pull pranks during chem class but the english and geography classes were fair game. Even the maths and physics classes experienced a little bang now and then.
In class the slightest shift of a student desk would trigger the paste on the floor. The huge bang and crimson smoke attracted undue attention. The "victim" was often blamed for the disruption.

Smoke bombs led to class evacuations; touch paste, exploding chalk as it touched the blackboard, Blackboard dusters exploded on contact. I was never caught. I told no one it was me.

The toilets were not safe. Mainly the female ones.
That's just briefly what I got up to. I won't admit I went to school in South Aust.

Cheers Marty

[Jen]

lol Marty you cheeky little devil you,
Dam it why wernt you around when i was at school we would have made a great team

[marki]

Originally Posted by Baddad

Hi Mark,

I'm reluctant to confess what I used to get up to in school. I was the top chem student and the Lab assistant was a close personal friend of mine. I learnt a lot very quickly. Youthful exuberance motivated me.

I never dared to pull pranks during chem class but the english and geography classes were fair game. Even the maths and physics classes experienced a little bang now and then.
In class the slightest shift of a student desk would trigger the paste on the floor. The huge bang and crimson smoke attracted undue attention. The "victim" was often blamed for the disruption.

Smoke bombs led to class evacuations; touch paste, exploding chalk as it touched the blackboard, Blackboard dusters exploded on contact. I was never caught. I told no one it was me.

The toilets were not safe. Mainly the female ones.
That's just briefly what I got up to. I won't admit I went to school in South Aust.

Cheers Marty

G'day Marty.

Well I am glad you didn't have my current formula because it certainly goes off with a bang and produces a lot of heat. I used to use another powder I would make up whilst doing afternoon labs at uni. Some of the reactions would take an age to complete so you mostly stood around starring at bubbling solutions and it could get very boring. Somehow the powder always seemed to find it's way under toilet seats and occasionally sprinkeled down the odd hall way or stair well. This stuff went off with a lot less of a bang then what I use now but it was always very amusing to watch people doing the touch powder dance when they came into contact with the stuff .

Mark

[Robert9 (Robert)]

Does anyone remember painting nitrogen tri-iodide (made by mixing potassium iodide and ammonia) into locker key-holes. Quite shock sensitive when it dries and as the key went into the lock .. bang and a puff of purple smoke.

Incidentally Mark, what are the employment opportunities for chemists these days? I recall getting my first appointment with ICIANZ Research back in the late '50s. Easy! Wrote a letter asking for a job (not advertised), went on holidays, came back, had an interview, got a job! Not so easy nowadays I reckon.
Robert

[marki]

Pretty low Robert. Over here it's all about mining so I try to direct my students interested in making a living from chemistry toward hydro and extractive metallurgy or chemical engineering. The vast majority of bright students will end up heading for engineering in any case. The mines are a little quiet right now but that will change in the near future if BHP and Rio Tinto don't completely destroy our relationship with the Chinese.

Mark

[Robert9 (Robert)]

Pharmaceutics may also be a reasonable direction. But, like anything else outside the mining industry, this too would probably mean moving to the eastern states. Has all the basic chemistry research been done? Or is this a reflection of modern society who are scared stiff of anything called a chemical. If only people realised that everything in existence is a chemical of some sort - even water!
What really gets me is when I hear of foods labelled "organic". I'd like to see someone eat inorganic foods. Bit tough on the teeth.
Robert