Showing posts with label Chemistry. Show all posts
Showing posts with label Chemistry. Show all posts
Nitrocellulose - the gun cotton

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
How to Play tennis using soap bubbles  and a carpet racket

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.
Flame test as you never seen before

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.
pharaoh's snake

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.


Safety:
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.
Eggshel and vinegar - reaction to make a rubber egg

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.
Rainbow juice using a Universal indicator

Rainbow juice using a Universal indicator


Universal indicator is used to find out the approximated PH of some substance. This video shows at first a ph 14. As some acid is added the color starts to changes. In the end the beakers bottom have a different ph from the top, so the various colors appears.
Chemistry Experiment - How to make a mirror

Chemistry Experiment - How to make a mirror



Mirrors always fascinating the human being, the possibility to look ourselves face to face is a mark in a culture of a people. That’s why these objects were so precious in ancient times and still are for some indigenous tribes.
Nowadays it is used, beside the self admiration, in cameras, telescopes and satellites.
When the man first went to the moon, they left a mirror there, so today using a laser is possible to measure the distance earth moon very accurately.
This videos shows how to make a mirror by using the glucose to reduce a silver complex. The metallic silver is deposited in the flask forming a mirror’s surface.
Learn how to do a sodium dichromate volcano

Learn how to do a sodium dichromate volcano

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Sodium dichromate is a orange solid. During its decomposition N2 , water and chrome oxide are liberated. The total volume increase in about 30 times. Some chrome oxide dust and the heat liberated make it really seamed with a true volcano.

Sodium Acetate Slow Crystalization

Sodium Acetate Slow Crystalization


"A single seed crystal was added to the saturated sodium Acetate solution while at 30C. Omnidirectional needle-like crystals radiated outward from the seed on contact at the solution's surface."
From: youtube video description
The magic of polyurethane foam: polyol and isocyante

The magic of polyurethane foam: polyol and isocyante

http://www.youtube.com/watch?v=RwJr6Iugcrkendofvid
[starttext]
This videos shows how polyurethane foam is made, you need just mix together the polyol and the isocyanete. A chemical reaction will happen and the total volume will grow up 30 times the original size.
[endtext]
Nitric Acid and a Penny

Nitric Acid and a Penny


When we put a penny in a flask containing nitric acid a chemical reaction happens, liberating nitrogen dioxide as a gas.

"Warning: Do not attempt this reaction. The gases produced are dangerous and must be properly controlled and ventilated. Also, the concentrated nitric acid used can cause severe acid burns.

If you've been keeping up, you know that we already popped a small balloon, but our intention all along was to go big. After purchasing larger balloons, we did a test run... and it was still essentially a flop. In this experiment, we use a snazzy apparatus with dual layered balloons to combat the corrosive nature of the Nitrogen Dioxide gas (and it really is corrosive).

The liquid in the first flask is concentrated Nitric Acid. When we placed a number of pennies in the flask, the acid reacted with the copper and released the nitrogen dioxide. The blue color in the copper solution is due to the copper ions.

You will notice a sort of double pop, and that is due to our double balloon layer. Contrary to popular belief, it is not magic.

If you're observant, you will also notice just how corroded the popped balloons did get. And, if you can take your eyes away from the balloons and smoke, check out the blue acid solution boiling in the foreground.

The overall after hours reaction should be considered a success, and hopefully you will find our diligent and persistent work to be enjoyable :)"
From: GWNProductions youtube channel
Science Experiments: Magic soap bubbles

Science Experiments: Magic soap bubbles


Baking soda and vinegar are very useful in science experiments, here we have another example in which this materials are used to amaze the people!
Put some vinegar in a aquarium, latter put some baking soda. The result of reaction is sodium acetate and carbon dioxide.
The CO2 is more dense than the air, so a soap bubble will float on it as a boat float on water. The buoyancy force is equal the weight of the bubble, thus we have the equilibrium and the bubble remains on interface CO2 / Air
Amazing science experiment: “nothing”  put the candles out

Amazing science experiment: “nothing” put the candles out


What this video shows seems a magic trick but is pure science!
Baking soda (sodium bicarbonate) when is mixed up with vinegar (acetic acid) produces a gas called carbon dioxide. This gas fill the space around the candle flame and put it out because there is no oxygen, essential to combustion.
Some fire extinguishers use this kind of gas.