Question

Uyeno’s method for preparation of hydrogen involves action of:
\[(a)\] Water on sodium hydride
\[(b)\] $KOH$ on scrap aluminum or silicon.
\[(c)\] Pure dil. \[SO\] on magnesium ribbon
\[(d)\] Aqueous alkali on zinc

Answer 1

Hint: Hydrogen can be produced using a number of different processes. Water can also be split into hydrogen and oxygen using electrolyte and solar energy. Hydrogen fuel is the next level for production of energy.

Complete answer:
The Uyeno’s method is used for the production of pure hydrogen for military purposes. The Uyeno’s method involves the action of $KOH$ on scrap aluminum.
$2Al + 2KOH + 2{H_2}O \to 2KAl{O_2} + 3{H_2}$
Some chemical properties of pure hydrogen are:
The \[H - H\] bond dissociation energy is the highest for a single bond between two atoms of any element.
It is highly combustible gas and burns in air or oxygen with a pale blue flame to form water.
Dihydrogen reacts with strongly electropositive metals like sodium, potassium at high temperatures to form salt-like metal hydrides.
Dihydrogen acts as a reducing agent and hence reduces oxides of certain metals less electropositive than zinc such as copper.
Hydrogen is used in a fuel cell for generating electrical energy, it does not cause any pollution and produces greater energy per unit mass of fuel in comparison to gasoline and other fuels.

Note:
There are many processes for the production of dihydrogen for industrial purposes like the Syngas- Bosch process or the electrolysis of water or from the hydrocarbons that produce hydrogen in large amounts. The most common method for producing hydrogen is steam-methane reforming.