27 replies to this topic

[W.P]

Today during chemistry classes our teacher decided to do a little demonstration of exothermic reactions. Although highly unnecessary he has a compulsion to demonstrate as much as he can practically in order to help us remember, however today was a step too far!

He first started off with a basic thermite demonstration, I'm guessing he placed around a gram or two in a crucible inside a dish of sand. Nothing fancy, lit the magnesium ribbon and the thermite reaction took place, everyone in the class being "amazed at the wonders of chemicals" except me, expected. Next he took another crucible and placed it on top of a gauze above a lit bunsen burner, told us it was "just some black copper oxide" then set us some paper work to get on with.

Around 5 minutes later there was a loud "thud" noise accompanied with a bright flash and a cloud of black smoke (this was INSIDE the lab by the way). The observation screens protected us from the flying pieces of ceramics and obviously everyone was surprised. I looked at him, his cheesy grin masking what I believed to be sheer ignorance or plain insanity! I told him "that was NOT JUST copper oxide was it, sir."

He responded almost under his breath as to not inform the class of what the actual contents of the crucible, in case they try to repeat this experiment. It was actually black copper oxide and magnesium mixed together. I asked him whilst recovering from the black smoke exactly how much was in the crucible, turned out to be eight grams. So not only did he just create 8g of flash powder he also placed it in a ceramic crucible (which is almost famous for it's tendency to fragment) but then placed it above a bunsen burner behind a class of students.

I asked him a third question: "Where did you get this idea from?". He responded with "I tried it earlier just to see if it would work, but the first time I was peering over the observation screen just to check whether a reaction was taking place and 'poof!' up in my face it went!". Bare in mind this man has a Master's Degree in chemistry.

Insanity or Stupidity?

[RangerOfFire]

Stupidity, the fact that he can comprehend what he's doing rules out insanity.

Reminds me of a chemistry teacher at my school who quit a couple of years ago. He always disregarded instructions and used way more than he should have.

On one experiment "jelly baby experiment" he used 3 times the amount of reactants and smoked out the top floor of the science block which also set off the school wide fire alarms....

[spectrum]

Thank god there are still some good old fashioned teachers out there!! This guy may be chancing his arm but he is, at the same time, demonstrating what a marvellous, exciting and beautiful subject Chemistry is. I should value him, next year you will might have some dreary old wet-blanket dribbling vinegar onto Bicarbonate of Soda having spent hours of preparation filling out risk assessments. I seriously think the subject should be taught with a little more imagination and we might inspire more young people to follow it.

[Asteroid]

It say foolishness more than stupidity. I am suprised he used it again after the first time, but maybe he thought just used too much. Perhaps it was a risk to take, but this is the kind of enthusiastic teaching i wish there was more of. He had the safety screens up and yes it was dangerous however this is what (for me) makes chemistry fun. Obviously I don't want shrapnelised earthenware everywhere, but let's be honest, changing the colour of lemon juice with universal indicator really doesnt cut it. I don't want this to come across as condoning it, but with a bit toned down a little it should be fine, at least he'll know for next time.

[GZ22]

Reminds me of my old chemistry teacher many years ago, Dr.Clarke. On the first chemistry lesson ever in secondary school, he made tear gas and mustard gas indoors, and only opened the windows when we began to choke! I agree with Spectrum - teachers like this reveal the beauty of chemistry, and help to foster an interest in the subject in young minds. A rapidly diminishing breed.

[Arthur Brown]

All the exciting things about Chemistry are verging on the insane! And it's my degree subject!

Your teacher is trying to keep the interest of lots of pupils, of different levels of prior knowledge. As he is meant to do it teaching requires you to wear safety goggles to look at the board if it has a chemical's name on there. Treasure this teacher, they are pushing the envelope as far as they dare, to keep the class interested and motivated. He likely realises that he class are robust enough and will assist you all to progress. Without him your lessons will be just boards full of equations a foot long, the class will get bored and you will lose information as he has to work to control the class.

There was a Dr Shaw (who also had military rank) who used to do theatre shows specifically for secondary schoolchildren - two hours of excitement lots of bangs -tallow candle through barn door, coin detonated into a metal sheet leaving a perfect imprint, and all the rest of the Chemist's party pieces.

There is a new series of lectures like, doing the rounds by a very competent and entertaining chemist with a great competence in pyro, fireworks, and HE work. Certainly there is one of his talks in the RAH in London, where the rest are..... I may hear or if he sees this he may post.

Edited by Arthur Brown, 30 October 2007 - 07:33 PM.

[Asteroid]

I'm glad that people agree with me. most kids today are preconditioned to think that science is boring, which it can be if it's taught by some dreary teacher who just wants you to copy things down and answer questions. A few bangs is probably what enticed everyone here into pyrotechnics and through it, whether you realise it or not into learning a lot of chemistry. I certainly find my love for pyro occasionally branches into other bits of chemistry and as a result I find chemistry much easier than most.
Any idea when the talks at the RAH are Arthur Brown?

[Arthur Brown]

The presenter for the talks wanders in here sometimes, but is likely to be busy this season. When next I see him I will ask, and ask about ticket availability. Just wait til the silly season is over!

Or you could ring the RAH and ask!

[spectrum]

A really dangerous experiment!!. Whilst at college many moons ago one of our lecturers recounted a lovely story from his own university days. Apparently a lecturer had a favourite demonstration whereby he prepared a wet mix of Potassium Chlorate and red Phosphorus and applied the mix with a paintbrush to one side of an old penny. This was placed painted side up on a sheet of 1/4 inch mild steel plate and the laboratory locked shut. The preparation was done last thing in the morning and first thing in the afternoon, the class returned to the lab and the lecturer when ready, tickled the penny with a feather on the end of a long bamboo cane. The explosion which followed was, without fail, powerful enough to punch a hole through the steel plate. But an OBVIOUS word of warning from someone who has worked with RP for many years (I am sorry to preach) it really is the most unforgiving mixture and the contamination gets everywhere. So please don't even think about trying this one out. I mention it as an example Not to inspire. My own Chemistry teacher was known to drop large chunks of Sodium metal into a bucket of water (on the school field), we did the thermite reaction and on one occassion, a balloon inflated with a mixture of Acetylene and Oxygen, pushed into the flame of a nearby bunsen burner - now THAT made a bang. All these things inspired me except the teacher who, ironically, was a complete shit to me, excuse my french.

[Andrew]

Both those experiments are on the current GCSE curriculum!

They are both thermit reactions (not flash).

Thank god there are still some good old fashioned teachers out there!! This guy may be chancing his arm but he is, at the same time, demonstrating what a marvellous, exciting and beautiful subject Chemistry is. I should value him, next year you will might have some dreary old wet-blanket dribbling vinegar onto Bicarbonate of Soda having spent hours of preparation filling out risk assessments. I seriously think the subject should be taught with a little more imagination and we might inspire more young people to follow it.

Here here!


On that note of inducing intrigue, I'm currently working with a friend who is a school chemistry teacher to organise this term's science club experiments. The pupils are making Roman Candles. These sets of experiments are just a trial which under government funding and various bodies that I have already got involved, should hopefully propagate throughout schools either next year or the year after. Just to give a gauge of numbers this has inspired to get involved, at the end of the last school year, there were 24 rather lethargically infused die-hard kids that wanted to do "science and engineering club" this year. The first week back it was announced in class what the first experiments will be. Within the week of this over 60 pupils signed up, countless others missed the boat and didn't get to sign up. Now massively over subscribed it was even considered to have two nights of the club. That's how to get the young disinterested involved in science!

Edited by Andrew, 31 October 2007 - 09:29 AM.

[YT2095]

I have a Mixed opinion about this, I think it was Really stupid to use a ceramic crucible, 1) it`s Very dangerous 2) it`s a waste of good Labware where a shallow walled nickel or Steel crucible would have done the same and been reusable after.

with that out the way, look at it like this, Did it get your Attention?
are you likely to Forget this?
Did it promote Questions? (I think we know it did)

so Job well done IMO

[W.P]

with that out the way, look at it like this, Did it get your Attention?

Just distracted us.

are you likely to Forget this?

I already knew most of what the subject was on.

Did it promote Questions? (I think we know it did)

Not really.

Walking to my physics class I see the bunsen burner on again behind the observation screen, the same teacher walking out the room. I asked him "still playing with chemicals sir?" and he responded "Shhh... it's 16g this time!".

[BrightStar]

I had at least three memorable chemistry teachers at school.

The first unfortunately filled a large glass apparatus with hydrogen and air mix and blew out the windows of the lab. Six months later, she demonstrated thermite just outside, unfortunately on a bed of wet sand. The steam explosion blew in the remaining windows. This finally got her sacked.

Another, known only as B****** was genial and scatty and just let us get on with our own work... nitrating cotton wool at the back of the class was informative, as were the occasional sodium nitrate flares

The best of the bunch was Dr P. In a memorable experiment, we were told to melt KNO3 in a boiling tube and NOT, under any circumstances (he said with a big grin...) to get our wooden splints near the tubes. Of course, once everything was good and hot, the already charcoaled splints met the tubes with fountains showers of sparks and much delight. We had reasonable PPE, so there was little real risk, but oddly, most of us who survived that practical signed up to his A-level course

Edited by BrightStar, 31 October 2007 - 07:49 PM.

[Creepin_pyro]

~10g of Copper thermite will happily hurl chunks of molten Copper a good few meters... surprised noone got a facefull, especially the teacher when he was peering over the observation screen when it went off!

I'm not sure what he thought the point of the experiment was - telling the class 'that's just some copper oxide there' and then watching it explode isn't going to teach them anything about chemistry! Infact, it's quite misleading and would probably just confuse someone.

I couldn't fault his intentions, but he was stupid about the way in which he carried out the experiment.

Andrew, are they really making candles? Live? On school premesis or elsewhere? How the hell did that one get by H&S? I'm impressed!

[EnigmaticBiker]

On that note of inducing intrigue, I'm currently working with a friend who is a school chemistry teacher to organise this term's science club experiments. The pupils are making Roman Candles.

Brilliant, a rare treat for me to be surprised!
Great to hear that people are actually getting this sort of project into schools (past all the insurers, nannies and lawyers etc).
The interest from the students speaks for itself.