Question

Describe the industrial preparation of Hydrogen by the electrolysis of water.

Answer 1

Electrolysis: The process of decomposing ionic compounds into their elements by passing an electric current through the compound in a fluid form.

Electrolytic cell: An electrolytic cell is a device in which electrical energy is converted into chemical energy.

• It consists of two electrodes that are held apart from each other and are in contact with an electrolyte.
• An electrode is a conductor made of graphite or metals used in an electrolytic cell and it conducts electricity.
• The electrode connected to the positive terminal of an electrolytic cell is called the anode.
• The electrode connected to the negative terminal is called the cathode.

Industrial preparation of Hydrogen by the electrolysis of water: Hydrogen is produced when an electric current is passed through water.

• A few drops of dilute Sulphuric acid or a few pellets of Sodium hydroxide are added to water to make it a better conductor of electricity.
• This process is called the electrolysis of water.

$$\begin{gathered} 2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\stackrel{\mathrm{electric}\mathrm{current}}{\to }2{\mathrm{H}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right) \\ \mathrm{Acidified}\mathrm{water}\mathrm{Hydrogen}\mathrm{Oxygen} \end{gathered}$$

• Here, acidified water is an electrolyte.
• Some compounds conduct electricity in their aqueous solution or molten state to undergo decomposition into ions, Such compounds are called electrolytes.
• $\mathrm{HCl},$${\mathrm{HNO}}_3,$${\mathrm{H}}_2{\mathrm{SO}}_4,$$\mathrm{KOH}$,$\mathrm{NaOH}$ solutions, ${\mathrm{PbBr}}_2$(molten), and (aqueous) are some examples of electrolytes.
• When electric current using a cell or battery is passed through the electrodes of an electrolytic cell, cations (Hydrogen ions) move towards the cathode, and anions (Oxide ions) move towards the anode of the electrolytic cell.
• In the electrolysis of water, Oxygen is produced at the anode, and Hydrogen is produced at the cathode