Question

preparation of Hydrogen

Answer 1

Preparation of Hydrogen 

Hydrogen gas is prepared in the laboratory by the action of dilute hydrochloric acid or dilute sulphuric acid on granulated zinc.

Zn + 2HCL → ZnCL₂ + H₂↑
Zn + H2SO₄ → ZnSO₄ + H₂↑

Granulated zinc is commercial zinc obtained from molten zinc. It contains impurities like copper which have a slight catalytic effect on the reaction and speeds up the reaction.

Answer 2

Hydrogen can be prepared by addition of metal and acid .

$\huge\underline{\textbf{Examples}}$

$\bigstar Zn+H_2SO_4\rightarrow ZnSO_4+H_2\\\\\bigstar Zn + 2HCl \rightarrow ZnCl_2+H_2$

Generally a strong acid is used in the preparation.

Granulated zinc is used for the preparation as it is easily available and has less impurities .

$\huge\textbf{\underline{TEST}}$

$\bigstar \textsf{Hydrogen is a colourless and odourless gas}\\\\\bigstar \textsf{It extinguishes a burning splinter with a pop sound}$

$\textbf{COLLECTION}$

Hydrogen is lighter than air and hence collected by the downward displacement of air .