Electrolysis is a process that involves the decomposition of an electrolyte by the passage of an electric current through it. In this process, the electrolyte is split into its constituent ions, which migrate towards the electrodes and undergo a chemical reaction.



When NaCl is dissolved in water, it dissociates into Na+ and Cl- ions. During electrolysis, these ions move towards the electrodes. The positively charged Na+ ions move towards the negative electrode (cathode), while the negatively charged Cl- ions move towards the positive electrode (anode).

At the cathode: Na+ ions gain electrons and are reduced to form Na metal.

Na+ + e- → Na

At the anode: Cl- ions lose electrons and are oxidized to form Cl2 gas.

2Cl- → Cl2 + 2e-

As a result of these reactions, the concentration of Na+ and Cl- ions decreases in the solution, while the concentration of Na metal and Cl2 gas increases.



The pH of a solution is a measure of its acidity or basicity. It is defined as the negative logarithm of the hydrogen ion concentration ([H+]) in the solution.

In the case of a NaCl solution, the pH depends on the concentration of H+ and OH- ions, which are produced by the dissociation of water.

H2O → H+ + OH-

The H+ ions combine with the Cl- ions to form HCl, which is a strong acid.

H+ + Cl- → HCl

The OH- ions combine with the Na+ ions to form NaOH, which is a strong base.

Na+ + OH- → NaOH

During electrolysis, the concentration of H+ and OH- ions changes due to the reactions at the electrodes.

At the cathode: H+ ions gain electrons and are reduced to form H2 gas.

2H+ + 2e- → H2

At the anode: OH- ions lose electrons and are oxidized to form O2 gas.

4OH- → O2 + 2H2O + 4e-

As a result of these reactions, the concentration of H+ ions decreases, while the concentration of OH- ions increases.

The pH of the solution can be calculated using the following formula:

pH = -log[H+]

where [H+] is the hydrogen ion concentration in moles per liter (M).

The initial concentration of H+ ions in the solution is equal to the concentration of Na+ ions, which is 1M. However, during electrolysis, the concentration of H+ ions decreases due to their reduction at the cathode.

The amount of H+ ions consumed can be calculated using Faraday's law, which states that the amount of a substance produced or consumed during electrolysis is proportional to the amount of electricity (in coulombs) passed through the solution.

Q = It

where Q is the amount of electricity, I is the current, and t is the time.

In this case, the amount of H+ ions consumed is equal to the amount of