Showing posts with label Chemistry. Show all posts
Showing posts with label Chemistry. Show all posts
Wednesday, January 27, 2010

Nitrocellulose - the gun cotton

Nitrocellulose, an explosive similar to nitroglicerin but, instead of glicerin, it has cellulosis on its composition. It is not sensitive to impact just to heat.
It burns so fast that there is no time to exchange heat with the hand
Tuesday, January 26, 2010

How to Play tennis using soap bubbles and a carpet racket

This video shows how to play tennis using a soap bubbles and a carpet racket. The soap bubbles are formed by a doubled layer of soap at extremities and a layer of water at center.
The polar part of soap molecules are bonded to the water and the nonpolar part are on the outer side.
Carpet is composed of polyester, as the bubble's outer side, so the interaction between them is very weak and the bubble do not pop out.
Monday, January 25, 2010

Flame test as you never seen before

Each chemical element has its own Identity given by the color emited when it is burning. The colors in fireworks is due a diferent kind of elements. Copper give the color green, sodium give the yellow one. This video shows a lot of diferent elements and its correspondent colors.

Oxydation of glycerine by potassium permanganate

Glycerine or glicerol is oxidized by a very powerfull oxidant, the potassium permanganete. This reaction liberates a lot of heat, it's called exothermic reaction.

Science experiment - how to make butter

Learn about science and you make your own butter. Science has never tasted so good.
Sunday, January 24, 2010

pharaoh's snake

That is very very dangerous.... be sure of what are you doing ....
"This is a piece of mercury thiocyanide. When decomposing, it makes large volume of ash, much larger than the piece of mercury thiocyanide itself.
By popular demand, here is a recipe to prepare mercury thiocyanide:

You need:
1. concentrated nitric acid (HNO3)
2. mercury (Hg) - from chemist or from thermometers
(alternative - buy mercury nitrate)
3. sodium or potassium thiocyanide (NaSCN or KSCN)

First, dissolve mercury in nitric acid to get mercury nitrate solution.

With concentrated nitric acid your mercury nitrate will probably crystallize - add
sufficient clean water to dissolve the crystals (say, 10 times the volume of nitric acid used).
(Alternatively: dissolve crystals of mercury nitrate in water)
In separate container, dissolve some sodium/potassium thiocyanide in water.
Add thiocyanide solution to mercury nitrate solution and mix it well.
Greyish suspension of insoluble mercury thiocyanide will form - wash with water a couple
of times (add water, mix, wait for mercury thiocyanide to separate at the bottom, decand/remove clear water, repeat.
Put paper coffee filter into funnel and filter out the mercury thiocyanide, dry iy - must be bone dry to use it.

Nitric acid is dangerous, handle with safety glasses, wash your hands immediately if spilled.
Vapours of mercury are dangerous - best gandle on open air.
Sodium or potassium thiocyanide is not that dangerous but don't leave solution for anyone to drink!
When dissolving the mercury in nitric acid, vapours of nitrogen oxides will form - these are poisonous if inhaled.
While decomposing, mercury thiocyanide forms fumes - don't know what they contain but make sure you burn it in open air (and NOT in your bedroom! ;-) and stand against the wind to prevent the fumes from inhaling." From: youtube description video.
Friday, January 22, 2010

Eggshel and vinegar - reaction to make a rubber egg

The eggshell has calcium carbonate in its composition. Acids as vinegar (acetic acid) reacts with calcium carbonate generating calcium acetate and carbon dioxide. After all calcium carbonate be consumed will remain just the proteins of the eggshell making a elastic shell.

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