Final answer:
Electrolysis is the process of using electricity to decompose hydrochloric acid (HCl) into hydrogen and chlorine gases. It involves the movement of H+ and Cl− ions to the cathode and anode, respectively, where they undergo reduction and oxidation to form the gases.
Step-by-step explanation:
Electrolysis is a technique used to decompose compounds into their elements using an electric current. When hydrochloric acid (HCl) is subjected to electrolysis, it breaks down into hydrogen and chlorine gas. This process involves dissolving HCl in water, where it dissociates into hydrogen cations (H+) and chloride anions (Cl−). The dissolved ions carry the electric current through the solution, allowing the reaction to occur.
During electrolysis, inert electrodes are inserted into the HCl solution. Upon applying a voltage between the electrodes, the hydrogen cations move towards the cathode (negative electrode), where they gain electrons (reduction) and form hydrogen gas. Meanwhile, the chloride anions move towards the anode (positive electrode), where they lose electrons (oxidation) and form chlorine gas. The overall chemical reactions are:
- Cathode (reduction): 2H+(aq) + 2e− → H2(g)
- Anode (oxidation): 2Cl−(aq) → Cl2(g) + 2e−
This decomposition process is an example of a nonspontaneous reaction, where the addition of electrical energy drives the reaction to occur.