Hydrogen – Notes
Dihydrogen: Preparation
Hydrogen is the most abundant element in the universe.
It has three isotopes – protium, deuterium and tritium.
In spite of its resemblance to both alkali metals and halogens, it occupies a separate place in the periodic table due to its unique behavior.
Its unique behavior also makes it a commercially important element.
In the laboratory, it is prepared by the reaction of zinc with dilute hydrochloric acid or with aqueous alkali.
Commercially, it is usually obtained from petro-chemicals, coal and by the electrolysis of aqueous solutions.
Dihydrogen: Properties and Uses
Dihydrogen is a colourless, odourless, tasteless, non-poisonous gas.
The small size of hydrogen atoms is responsible for its unique properties.
Dihydrogen gas is inert at room temperature.




