YOUCHEMISTRY

3 Mar 2012

Isotopic effect of heavy water

from chemToddler



D2O, colloquially referred as heavy water, is normal water (H2O) highly enriched in the hydrogen isotope deuterium, which is twice as heavy as normal hydrogen. Deuterium oxide (D2O) it is about 11% denser than water, but otherwise, is physically and chemically similar. This video nicely explains this heavy water term.

29 Feb 2012

Lightbulb in liquid nitrogen

from TheBlueginjava



A bare wolfram lightbulb filament in a beaker of liquid nitrogen can be connected to an electric current safely and without decomposition of the filament, shining as a normal lightbulb. The liquid nitrogen is a non conductive and almost inert material that isolates the wolfram filament from the atmospheric oxygen that would burn it out. The video explains it very well!!

25 Feb 2012

Liquid Nitrogen Explosion

Steve Spangler Science




Liquid nitrogen (boiling point -196 ºC) evaporates very quickly (explosively) in contact with hot water....

Brainiac Alkali Metals

from scientist303




Alkali metals react with water reducing its protons to H2(g) and leaving an alkaline aqueous solution due to alkali metal hydroxide formation. When going down in the group from lithium to cesium the alkali metals give its electrons to the protons of water more easily and the reaction goes faster. As the reaction release heat, if this heat cannot be dissipated quickly enough the hydrogen released will get ignited, sometimes very violently, and react with atmospheric oxygen forming water again.

M(s) + H2O(l) = M(OH)(ac) + 1/2 H2(g) + lots of energy(*)!!...
H2(g) + ½ O2(g) + ignition energy(*) = H2O (g)!! + lots of energy!!...