Cou
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High school chemistry classes in texas
I live in texas, and here's the weird thing about my school's chemistry labs: They have many hundreds of dollars worth of many dangerous chemicals,
such as a gallon jug of concentrated nitric acid. And a lot of rare goodies that I long for. But weirdly enough, they buy all this stuff, but never
use it in class, because of the fear of getting sued. And they're even less likely to let a student borrow reagents and equipment. Myself, I'm hoping
I can get 2 carbon electrodes.
Why do you think this is? Why would the school spend so much tax money on chemicals that just sit in the backroom without ever getting used?
[Edited on 14-10-2014 by Cou]
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Texium
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I noticed the same thing at my school last year in my first chemistry class. This year I'm in AP chemistry though, and I've noticed that we use a lot
more expensive and/or dangerous reagents than we did last year.
Some of the stuff might just be old and not used in the curriculum anymore. For example, my chemistry teacher (who has been at the school for many
years) had a little bottle of indium pellets that had been around since before she was teaching there. They hadn't been used in ages. She let me have
some for my element collection since there were no plans to use them for anything.
[Edited on 10-14-2014 by zts16]
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numos
Hazard to Others
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Some chemicals are needed once and then just kept. I know I used Iodine within the first two weeks of AP Chem, however something like Potassium
dichromate was banned a while ago. Although we may have some, were not allowed to use it. Same with Bromine, Mercury compounds...
Also remember that as standards change certain labs become meaningless, or some experiments may result in a mess, or smells, or take to long and were
abandoned.
But as far as I've seen there is nothing in our labs that I really long for. Schools are good if you have a project in mind and need to buy from
Aldrich, as a school will be your only hope in that scenario.
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Bert
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I recently (late 2014) visited the chemistry and physics classrooms of the high school I attended in the 1970's.
They still had teaching and demonstration equipment that my father had advised the newly built high school to buy around 1964! (Dad was a state
university scientist, high energy physics/particle accelerators were his area of interest...)
The chemical supplies included items that students under the age of 18 would NEVER be allowed access to in these days. I would bet money some of those
bottles were there 40 years ago when I was a young teen, and had survived remodeling of the school and moves to new class room supply closets without
ever having been opened-
I spoke with the senior physics and chemistry instructor at some length. When I described the things I was allowed to do by MY teacher he visibly
cringed. (drop a crystal of elemental Iodine on some molten white Phosphorous? Sure! Just wear your goggles & gloves, close the hood most of the
way and keep amounts small...)
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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Texium
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Reminds me of a story my chemistry teacher told us about how a chemistry teacher at Austin High, one of the oldest high schools in the area, asked her
for advice about disposing of a gallon of hydrofluoric acid that had been on campus for decades... Needless to say, she was appalled at the notion of
dealing with that.
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Bert
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Oh, got to have several gallons of hydroflouric acid in any high school lab- If the chemistry teacher needs to dispose of any dead bodies, nothing else will substitute!
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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Brain&Force
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I've seen chromium sulfate on a lab shelf from 1988. (My teacher let me grab whatever I needed from the stockroom. I feel deeply honored.)
At the end of the day, simulating atoms doesn't beat working with the real things...
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j_sum1
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Let me add the perspective of a teacher here.
First some context. I was trained as a metallurgical engineer -- not really a chem specialist. Career took a convoluted path and I don't have a
whole lot of industrial experience. Ten years later I trained as a secondary (high school) teacher: math primarily but also science. At the
beginning of 2013 I took on the role of sole Chemistry teacher. Chem hasn't been my strong suit but I have grown to fill the role. It's been a whole
lot of fun.
Our school lab has a lot of old chemicals. Many are actually older than the school buildings and were presumably bought second-hand or donated at a
time when budget constraints were tighter. In a school, staff changes reasonably regularly and if the chemical inventory is to be looked after then
someone needs to make decisions about throwing stuff out. The bottom line on that is that only someone with a reasonable amount of knowledge can make
a call on whether a stocked chemical is useful. A person with that kind of knowledge will actually find a use for many chemicals. the result is that
no one throws anything out for years and years.
Add to this is that curriculum is in a constant state of change. The one constant being continually increased restrictions on what is allowed in a
school and what students are allowed to handle. For example we have probably around 40g of potassium. That can never be replaced -- it is just not
allowed any more. So, no one in their right mind is going to get rid of it. On the other hand, it has a sense of being dangerous and so it is not
often used. Therefore it just hangs around in a jar of oil slowly oxidising.
Interesting things have taken place in my school. Health and safety regulations have forced a major cull of our chemical store. Any chemicals more
than a few years old are to be discarded if there is any doubt about their state or the state of the containers. At the same time I have been keen to
use up some chemicals if I can find a way of using them that fits in with what I am teaching. Anything that is truly useful gets replaced. There is
a bunch of stuff that won't.
One of the results of this has been me researching on chemicals in the store to discover if there is anything useful that I can do with them. It has
been a great journey for me. And I think fun for my students. As I have learned new things I have also been able to push the boundaries on what
students do. They get experience in safe handling of chemicals that would not be allowed in most schools. I am very cautious with toxicity issues
but do allow reasonably energetic reactions. One of my students recently did an extended experimental investigation on thermite reactions. It was
interesting when he was completing his risk assessment documents when he came across guidelines saying students should not be handling powdered
aluminium. It's just a guideline. I taught him how to do what he was aiming to do safely. He gained a lot from it. Likewise we have made chlorine
gas and then done reactions with it. (Chlorine and acetylene is kind of memorable.) We have reacted sodium and sulfur. (crackle bang!) I have had
my senior students demonstrating various kinds of flame tests to juniors including burning metal samples.
A few specific chemicals tell their own story.
A large number of deliquescent chemicals were sitting in ancient bottles in a slurry. These have been replaced.
I found a deteriorated container of ethyl amide. It had probably not been used for 20 years. I had some students use the lot in an
investigation on solubility. We then replaced the bottle.
We have a couple of kg of mercury. The bottles are old but stable. I have no experimental use for mercury but think it is worthwhile hanging
on to it. It is really good for looking at the properties of elements.
We have some mercuric oxide. Decomposition to Hg and O2 is such an important experiment historically we will probably do it at some stage. I
am hanging on to it.
We have a couple of litres of Millon's reagent. That is being disposed of. If we ever have a need for it we will get some more. But it is
very unlikely.
I found a container of chromium trioxide sealed shut. I am really cautious with hexavalent chromium. And this stuff is highly energetic and a
powerful oxidant. I have found two possible ways we can use it. Just need to wait until the right teaching unit. After that I will make a call on
whether it should be replaced.
We have a number of ampoules of Bromine. Within the curriculum the only real use for bromine is bromine water for use in organic chemistry.
And that has a shelf life of only a year or so. It is surprisingly expensive from our normal suppliers. For making bromine water I will synthesise
what we need and then dispose when we have finished with it. But we will hang on to the ampoules. Again it is great to have students able to see
pure elements.
So, in summary, there are reasons why schools tend to accumulate and hang on to old chemicals. But I think that it makes for better teaching and
learning if the chemicals are actually used. It certainly helps my students that I am learning at the same time and seeking to push the boundaries.
We are aiming for good stock rotation than we had before and I think it is a safer and more productive work environment because of it.
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