|Hydrometallurgy||Crystal Structure||Forms of Corrosion|
2 CrO3 + C2H5OH + 3/2 O2==> Cr2O3 + 2 CO2 + 3 H2O
In this reaction fire is obtained from strong oxidizing agents by reacting it with inflammable organic components . The process involves a lot of heat as the reaction is exothermic, it releases huge heat which can ignite ordinary substances like paper
The reaction :-
Pb(NO3)2 + 2 KI ==> PbI2¯ + 2 KNO3
THE REACTION BETWEEN NITROUS-OXIDE OR NITROGEN MONOXIDE AND CARBON DISULPHIDE FORMS AN EXPLOSIVE MIXTURE .
WHEN THE MIXTURE IS IGNITED IN THE TUBE , THE SOUND OF A DOG BARKING COULD BE CLEARLY HEARD, EVEN THOUGH THERE IS NO DOG PRESENT . THE EXPLOSION BECOMES MORE VIOLENT WHEN THE TUBE'S DIAMETER IS INCREASED ,IT IS FOLLOWED BY A BLUE FLAME. THIS PECULIAR SOUND IS HEARD AS THE MIXTURE MOVES MODERATELY IN THE TEST TUBE. THE REACTION :-
3 NO + CS2==> 3/2 N2 + CO + SO2 + 1/8 S8
4 NO + CS2==> 2 N2 + CO2 + SO2 + 1/8 S8
Line the bottom of the pan with aluminum foil. Set the silver object on top of the aluminum foil. Make sure the silver touches the aluminum. To the hot water, add about one cup of baking soda for each gallon of water. The mixture will froth a bit and may spill over; this is why you put it in the sink. Pour the hot baking soda and water mixture into the pan, and completely cover the silver. All of the tarnish will disappear within minutes. If the silver is badly tarnished, you may need to reheat the baking soda and water mixture.
When silver tarnishes, it combines with sulfur and forms silver sulfide. Silver sulfide is black. When a thin coating of silver sulfide forms on the surface of silver, it darkens the silver. The silver can be returned to its former luster by removing the silver sulfide coating from the surface.
In the reaction, sulfur atoms are transferred from silver to aluminum, freeing the silver metal and forming aluminum sulfide. Chemists represent this reaction with a chemical equation.
|3 Ag2S||+||2 Al||=||6 Ag||+||Al2S3|
(NH4)2Cr2O7==> Cr2O3 + 4 H2O + N2 (13.1)
Normally this demonstration is performed as the classical Volcano experiment, so called because ash produced occupies a far greater volume than that of the original dichromate and so builds a ‘mountain’ of dark green ash with sparks and read heat emanating from a ‘Caldera’ at its summit.
Cl2 + 245.5 kJ = 2 Cl·
The cleavage of one mole of chlorine by photodissociation requires 1 mole of light quanta (hn). Since an amount of energy equal to 243.5 kJ corresponds to a wavelength of 491 nm, only blue light or light of even shorter wavelengths can be used, but not longer-wavelength yellow or red light. Thus the chlorine-hydrogen reaction is initiated by blue light but not red light