Write an essay on the commericial preparation of dihydrogen. Give balanced equations.

Explanation

Commercial methods of preparation of dihydrogen
i) From Hydrocarbons : When hydrocarbons undergo reaction with steam at high temperatures in presence of catalyst liberates hydrogen gas.
Eg : `C_(3)H_(8(g))+3H_(2)O_((g))underset("Catalyst")overset(Delta)to3CO+7H_(2)`
ii) By the electrolysis of water :-Acidified (or) alkaline water undergo electrolysis using platinum electrodes liberates hydrogen gas.
`2H_(2)O_((l))underset(H^(+)//OH^(-))overset("Electrolysis")to2H_(2(g))+O_(2(g))`
Highly pure hydrogen is liberated by the electrolysis of hot aq. `Ba(OH)_(2)` by using .Ni. electrodes.
iii) By Nelson.s Process : Hydrogen gas is obtained as a Byproduct by the electrolysis of brine solution. This process is mainly used for the manufacturing of `NaOH,Cl_(2)^(-)` gas.
Cell Reactions :
`2NaCl to2Na^(+)+2Cl^(-)`
`2Cl^(-)toCl_(2)+2e^(-)("Anode")`
`2H_(2)O+2e^(-)toH_(2)+2OH^(-)("Cathode")`
`2Na^(+)+2OH^(-)to2NaOH`
iv) By water gas shift reaction: Water gas is the mixture of CO and `H_(2)`. It is also called as syngas.
The process of producing syngas from coal is called as coal gasification.
`C_((s))+H_(2)O_((g))overset(1270K)toCO_((g))+H_(2(g))`
`to` The dihydrogen production can be increased by the reaction of steam with syngas in presence of catalyst.
`CO_((g))+H_(2)O_((g))underset("Catalyst")overset(673K)toCO_(2(g))+H_(2(g))`
This reaction is called as water gas shift reaction.