Reglas Del Laboratorio [Rules of the lab]

Due to the high explosion content in chemistry labs, chemists have a strict set of rules that must be adhered to while in the lab.

* Mix, shake, explode!
* If you don’t know what you are doing, do it anyway.
* Avogadro’s number works for everything – it’s magic!
* When in doubt, convert everything to moles.
* If you can not convert to moles, convert everything into gophers.
* If you need a straight line plot, use only two data points.
* When you don’t know what you’re doing, do it neatly.
* Most chemicals can be distinguished by taste, or by huffing them.
* In case of prolonged exposure to water, treat exposed area with concentrated hydrochloric acid, then rinse with sulfuric acid.
* Dry ice should be held firmly at all times, without gloves of any kind.
* Experiments must be reproducible. They should fail the same way each time.
* First draw your curves, then plot your data.
* Warning labels are for pussies.
* If you can’t get the answer in the usual manner, start at the answer and derive the question.
* In case of doubt, make it sound convincing.
* Do not believe in miracles – rely on them.
* Liquid nitrogen is to be thrown at other people.
* The glasses and coat really do make you look awesome. Wear them to increase your sex appeal.
* The answer to number 2 is D.
* When unsure of what to do, just throw chemicals together until something explodes.
* Team work is essential – it allows you to blame someone else.
* No experiment is a complete failure. At least it can serve as a negative example.
* Any delicate and expensive piece of glassware will break before any use can be made of it.
* All unmarked beakers contain highly toxic, fast-acting poisons.
* If you hear an explosion, first check your pants.
* If you find something in your pants wash it out quickly with highly concentrated bleach to avoid the ridicule of other chemists.
* Look to political science or the church for help when you are stuck on a problem (good luck).
* After heating a substance, touch it to make sure it’s cooled down.
* Do something stupid ONLY when the teacher is watching.
* Remember, open flames are the safest flames.
* For unknown substances, always rely on the three T’s: touch, taste, and tequila.
* The only reason alcohol is an important experimental substance is because you are supposed to drink it, then experiment.
* Everything is better with big booms.
* Make sure to always change or make up data when they do not agree with your expectations.
* Always transfer chemicals using your mouth as a pipette.
* If you spill acid on the table, make sure to use your partner’s lab coat to clean it up, preferably when they’re not looking.
* Wash your eyes in the chemicals used in the experiment and then fail to use to eyewash station.
* The purpose of distilled water bottles is to squirt water at others.
* If you’re not first, you’re last.
* If you can’t clean it, break it.
* If you can’t break it, eat it.
* If you can’t eat it, force someone else to eat it.

Imágenes Del Laboratorio

A continuación figuran algunas imágenes que pertenecen al laboratorio de química de tercer año del colegio Otto Krause. Como verán las condiciones de trabajo puede que no sean las óptimas, pero con el esfuerzo de todos podemos avanzar.  

Banned: The Golden Book of Chemistry Experiments [DOWNLOAD]

Back in the late 60′s this book, written for Children, was pulled from all public libraries and store shelves by the government. It was said that the experiments and information contained herein were too dangerous for the general public. A big fuss was made of a 1995 incident near Detroit in which child chemist, David Hahn, attempted to build a nuclear breeder reactor in his backyard shed. A book by Ken Silverstein called ‘The Radioactive Boyscout’ tells the whole story, but you can get a summary on Wikipedia. This book is thoroughly interesting and is full of ideas and inspiration, it is the bible for any young chemist-in-training. Used copies on Amazon are rare and are currently priced between $237 and $690 for very used copies. However, because it was published in 1960, before the US copyright laws were rewritten, and because its original copyright was never renewed, it’s legal for me to share with you online.

 The Golden Book of Chemistry Experiments (DOWNLOAD PDF)

 

Preparación del ácido 4-vinilbenzoico por reacción de Wittig

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Procedimiento

1.- Preparación del ácido 4-bromometilbenzoico

Se colocan 2.7 g de ácido 4-metilbenzoico y 3.6 g de N-bromosuccinimida. Añadir el peróxido
de benzoílo con cuidado de que no se adhiera al esmerilado del matraz. Por último añadir 25 ml de
clorobencen, arrastrando el sólido que pudiera haber quedado en las paredes interiores del matraz.
Seguidamente se calienta la mezcla suavemente a reflujo durante 1 hora con agitación magnético.
Tras ese periodo se enfría el matraz en un baño de hielo durante 10 minutos y se filtra el precipitado
por succión. El residuo se lava con hexano (3×10 ml) y se transfiere a un vaso de precipitado. Se
añaden 50 ml de agua y se agita durante 10 minutos para disolver la succinimida. Se filtra, de nuevo
por succión y el precipitad se lava sucesivamente con agua (2×10 ml) y hexano (2×10 ml). Se seca el
producto pasando una corriente de aire en el Büchner. Se pesa u se usa en la siguiente etapa
(determinar el punto de fusión).

2. Preparación del bromuro de 4-carboxibenciltrifenoxofosfonio

Disolver el ácido 4-bromometilbenzoico (4.30g, 20 mmol) y la frifenilfosfina (5.20g, 20mmol) en
60 ml de acetona en un matraz de 100 ml. Refluir la mezcla durante 45 minutos. Tras ese
periodo,enfriar la mezcla de reacción y filtrar la sal de fosfonio precipitada por succión. Lavar el sólido
con éter dietílico y secarlo por succión. Pesar el producto, medirle el punto de fusión y usarlo en la
siguiente etapa.

3.- Preparación del ácido 4-vinilbenzoico

Colocar el bromuro de 4-carboxibenciltrifenilfosfonio (3.76g, 8 mmol), el formaldehído acuoso
(32 ml) y 15 ml de agua en un erlenmeyer de 250 ml, equipado con agitador magnético. Agitar
vigorosamente, sujetando el erlenmeyer con una pinza y añadir una disolución de hidróxido sódico
(2.5g en 15 ml de agua). Agitar la mezcla durante 45 minutos y filtrar el precipitado por succión,
lavándolo con agua. Acidificar el filtrado, y las aguas de lavado con ácido clorhídrico concentrado y
filtrar el precipitado resultante por succión. Recristalizar el producto con etanol acuoso y pesar.
Determinar el punto de fusión