The preparation of di hydrogen is by the electrolysis of acidified or alkaline water using platinum electrodes. Generally, 15 – 20% of an acid (H2SO4) or a base (NaOH) is used.
At the cathode, reduction of water occurs as:
\( 2H_{2}O+2e^{-}\rightarrow 2H_{2}+2OH^{-} \)
At the anode, oxidation of OH– ions takes place as:
\( 2OH^{-}\rightarrow H_{2}O+\dfrac{1}{2}O_{2}+2e^{-} \)
Net reaction is represented as
\( H_{2}O_{(1)}\rightarrow H_{2(g)}+\dfrac{1}{2}O_{2(g)} \)
Due to the absence of ions, the electrical conductivity of pure water is too low. Hence, electrolysis of pure water takes place at a low rate. The rate of electrolysis increases if an electrolyte such as an base or acid is added to the process. The electrolyte is added which makes the ions available in the process for the conduction of electricity and for electrolysis to take place.
Answered by Pragya Singh | 1 year agoWhat do you understand by the terms :
(i) Hydrogen economy
(ii) Hydrogenation
(iii) ‘syngas’
(iv) Water-gas shift reaction
(v) Fuel cell?
Do you expect different products in solution when aluminium (III) chloride and potassium chloride treated separately with
(i) alkaline water
(ii) acidified water, and
(iii) normal water. Write equations wherever necessary.
What do you expect the nature of hydrides is, if formed by elements of atomic numbers 15, 19, 23 and 44 with dihydrogen? Compare their behaviour with water.
How can saline hydrides remove traces of water from organic compounds?