Subject: Physics
The phenomenon of the passage of the electric current through liquids and their decomposition into ions as a result of it is called the chemical effect of electric current.
According to the ionic dissociation theory explained by Arrhenius, the molecules of an electrolyte exist in the form of ions even if the electrolyte is in the solid state. For example a common salt molecule (NaCl) exists in the form of ions even in the crystalline state i.e. \(NaCl \rightarrow Na^+ + Cl^- \). These ions are held together by the electrostatic force of attraction i.e. \( F = \frac {1}{4\pi \epsilon _0 \epsilon_r}\frac {Q_1Q_2}{r^2} \) where Q1 and Q2 are charged on two ions, r is the distance between them and ϵr be the relative permittivity of the medium between them.
When NaCl is dissolved in water (ϵr » 80), the force between them is lesser (1/80 times ) so they become free from each other’s attraction and, therefore, they get separated. When a potential difference is applied across the electrolyte, the cations, (Na+) moves towards cathode and anions (Cl-) move towards the anode. One reaching to the respective electrodes, the ions get discharged and then appears as deposits on the electrodes or get liberated as a free gas. This explains the conduction of electric current through an electrolyte.
The electrolyte conduct electricity, but their conductivity is very low than that of good conductor due to following reasons:
Voltameter is the vessel in which electrolysis is carried out. Following are the most common voltameter:
Reference
Manu Kumar Khatry, Manoj Kumar Thapa, et al.Principle of Physics. Kathmandu: Ayam publication PVT LTD, 2010.
S.K. Gautam, J.M. Pradhan. A text Book of Physics. Kathmandu: Surya Publication, 2003.
The phenomenon of the passage of the electric current through liquids and their decomposition into ions as a result of it is called the chemical effect of electric current.
Electrolysis is the process of decomposition of an electrolyte into its constituent ions by the passage of electric current through it.
The metal rods or plates which are partially dipped in the electrolyte solution for passing the current through it are called electrodes.
The process of decomposition of a compound into its constituent ions is called ionization.
© 2019-20 Kullabs. All Rights Reserved.