YOUCHEMISTRY

23 Feb 2012

SUGAR AND KClO3

from nuclearrabbit




Under thermal conditions or ignited by sulfuric acid, KClO3(s) decomposes to KCl(s) and 3/2 O2(g), which is a disproportionation reaction. The O2(g) generated oxidises very quickly carbohydrates as sucrose, C12H22O11(s,) liberating lots of heat, CO2(g) and H2O(g)...the presence of a bit of CuCl2(s) gives the bluish colour to the flames...very spectacular!!...

21 Feb 2012

Conductivity of Glass

from NatSciDemos

Insulating glass becomes a conductor of electricity when heated with a blowtorch.

At the beginning I thought it was a fake as when heating the remains of the broken bulb, the two metallic filaments inside it were put into contact again. However, the changes observed on the intensity of the working bulb when changing the temperature of the "glass switcher" make me thought that this is well real!!




Two ceramic lightbulb sockets are wired in series to a household AC power cord. When two incandescent bulbs of the same Wattage rating are screwed into the sockets and the cord is plugged in, they both pass the same amount of current and so they both light with the same intensity. When one bulb is unscrewed, the circuit is broken and the other bulb goes out. If we can replace the missing bulb with a conductive material, the circuit will once more be complete and the remaining bulb will light again.

14 Feb 2012

Thermoelectric generator

from henders007



The thermoelectric effect refers to phenomena by which either a temperature difference creates an electric potential or an electric potential creates a temperature difference. Converting temperature to current is known more specifically as the Seebeck effect.

This effect has been used for decades to power space vehicles (Apollo ,Voyager probes, Mars rovers, etc..) using radioisotope thermoelectric generators, where the heat released by the radioctive materials is converted into electricity using an array of thermocouples.

Commonly used thermoelectric materials in such applications are semiconductors, as for example bismuth telluride (Bi2Te3).

What are the car companies waiting for to install these devices in our cars!!