Question

How will you prepare oxygen at the ordinary temperature in laboratory. Give a balanced equation for the reaction.

Answer 1

From distillation of acidulated water:
Pure oxygen can be obtained by the electrolysis of water containing some acid or alkali. Oxygen is collected from the anode.
Preperation of Oxygen from acidulated water

Chemical reaction:
$H_{2}O\rightleftarrows H^{\oplus }+{\mathrm{OH}}^{\oplus }\mathrm{At}\mathrm{Cathod}:2H^{+}-2e\to H_2\left(g\right)\uparrow \mathrm{At}\mathrm{Anode}:4{\mathrm{OH}}^{-}-4e\to 2H_{2}O+O_2\left(g\right)\uparrow$