It was the end of
the 5th year, or as it had recently been rebranded, year 11. I was sitting in my physics class, and we were being bade farewell by our teacher, who for the purpose of this story I will refer to as The Prof.

I quite liked the prof. He was amiable enough but by the same token didn't take any shit, canny, slightly frosty, academic. He was at that indeterminate age all non-really old and non-really young teachers have. Around this time he first become a father. He was built like a rake and had a noticable stutter.

The Prof likewise quite liked my class, and he gave a little speech in our last lesson before we broke up for study leave, did our GCSEs and left school for sixth form college forever. To mark the occasion he chose to regale us with a story from the infancy of his career, around 18 months after he had qualified, which he rarely told.

His first post had been in a reasonable comprehensive much like ours, but being the newbie he tended to draw the short straw on all the lousy jobs. He liked our class because we were a top set, and he liked teaching top sets. The short straw, the job he hated most , was taking the remedial class. It seems the staff at his first school felt likewise. Being the newbie, he had been given the remedial class.

It didn't start auspiciously. He handed out fresh exercise books and told them to put their name and form on the front. At the end of the class he took the books back. The class weren't allowed to take them home as they would lose them. Half-a-dozen had spelt their name wrong.

He toiled with them till the end of the year. It was a general science class, so the prof didn't even get to specialise in physics. He found the class frustrating because they didn't learn anything, he just endlessly repeated the basics. At the end of the year, for the wont of doing something memorable with this class, he decided to give them something all kids like, no matter how dumb. An explosion.

The classroom had a fume cupboard at the back. Into it he put a clamp and stand and a perspex beaker. He then rigged up a pully system. It had a rope that ran under the door of the fume cupboard, round a hitch on the ceiling and hung above the beaker. The other end ran to the other side of the room and was tied off on a gas tap.

The class arrived, and he announced a treat. They clapped like retarded seals. Hydrochloric acid comes in large bottles and is diluted by technicians before being given to students. The neat acid has the viscosity of syrup. He half-filled the beaker with acid-syrup. He then found the largest lump of sodium he could find and tied it to the pully rope, above the beaker, loosely balanced on the clamp. He shut the door, turned on the extractor, and move the class to the back of the room.

He released the rope. It ran over the pully and the sodium dropped into the acid.

Nothing happened.

The prof was bemused. There should have been a bright, sparkly chemical reaction to impress the thickie children. There wasn't. The prof took a few steps towards the fume cupboard.

Then air pressure, a bang, boom, crash, a smell like bleach, an alarm going off. An explosion.

The beaker was gone. The clamp-stand had been bent into a "C" shape. The windows of the fume cupboard had bowed outwards. They had shattered but kept the glass as they were laced with wire. There were sparks and glows from where the beaker had stood as the last fragments of sodium reacted. The was the hint of a small fire. A layer of smoke lay across the ceiling.

One of the children asked if he could do it again. The building was evacuated.

The prof has no idea how he avoided the sack. He was censured and put on a final warning. So much as a fart out of place and he would be shown the door. He never did it again.

As the school was short on space, they cordoned the area around the fume cupboard off and had classes at the other end of the room. Not all the acid had reacted and had evaporated, and it slowly condensed on the inside of the shattered windows. Over the course of an hour class there would be half-a-dozen skittering tinkles as it chewed through the wire and allowed a fragment of glass to escape onto the floor.
( cs1ca, Sat 10 Sep 2011, 21:32, 3 replies)

I smell bullshit
a) Schools are supplied with 35% HCl, not fully conc.

b) If HCl had evaporated, you wouldn't have people alive and breathing in the same room, would you doofus? I spilled 1cc of 50% bromine a couple of years ago and that damn nearly killed me.
( ousgg is not seeking approval, Sat 10 Sep 2011, 23:20, closed)

Bullshit? Really?
No. I was told a story with roughly these details by my old physics teacher in 1992. There are tweaks for dramatic effect, but all the details are his.

HE may have been lying, sure, but bearing in mind this is framed as a story that I have been told, not something I have directly seen and done, I dare say most intelligent people could figure that possibility out for themselves.

In reply to a) + b), I wouldn't know as I neither work in a school, nor was I there, and nor do I claim either. Doofus.
( cs1ca, Sun 11 Sep 2011, 0:52, closed)

You don't need to work in a school
To understand that breathing in concentrated acid is not a great idea.

Anyway, I never said it was your bullshit. Could quite easily have been the prof's.
( ousgg is not seeking approval, Sun 11 Sep 2011, 8:20, closed)

Who cares?
Funny story, well told.

Find me a QOTW answer that is 100% true and I'll find you a b3tan who isn't a closet troll...
( ogwen69 has returned from Reddit, Sun 11 Sep 2011, 9:34, closed)

You don't need to work in a school
to understand that any anecdote will contain at lease some poetic licence.
( cs1ca, Sun 11 Sep 2011, 11:37, closed)

Concentrated HCl does not have the viscosity of syrup. Phosphoric acid does though, but that wouldn't give a smell of bleach. Whatever.
(Bitter and Twisted, Sun 11 Sep 2011, 19:08, closed)

This is great
I get to have the last conversation all over again!#

I thought this was question of the week, not mythbusters.
( cs1ca, Mon 12 Sep 2011, 19:58, closed)