Question

Which metal is preferred for the preparation of hydrogen gas from water?

Answer 1

Hint:Metals above hydrogen in the electrochemical series of the elements react water under different conditions to liberate hydrogen gas and the metals form their respective oxides.

Complete step by step solution:
According to the electrochemical series of the elements, where the elements are arranged according to their ability to get reduced or oxidised, those metals which are at the top of the group are highly reactive with ice or ice-cold water to form the respective metal oxide and liberate hydrogen gas. So due to the high reactivity of these metals, like sodium, potassium, etc. these metals cannot be chosen for the reaction to liberate hydrogen gas. Again when we move down the group, the elements lose their reactivity and metals like lead react at very high temperatures with steam to form the respective metal oxides and liberate hydrogen gas.

So, metals in the intermediate region like magnesium that react with hot water to liberate hydrogen gas is the best one for the preparation of hydrogen from water.

Note:
The hydrogen is the first element in the periodic table with the atomic number 1 and atomic weight 1. This is the lightest element in the periodic table. Hydrogen is the most available element in the universe. At standard temperature and pressure, hydrogen is colourless, odourless, neutral and tasteless gas. It is only sparingly soluble in water and is the major component of all the organic substances.