R is gas constant (8.314 JK–1 mol–1),
F is Faraday constant (96487 C mol–1), T is temperature in kelvin and [Mn+] is the concentration of the species, Mn
Strong electrolyte |
Weak electrolyte |
1. These have higher molar conductivities at all concentrations. 2. λ°m values increase very slightly with dilution. 3. Degree of ionisation is very high at all concentration i.e., almost fully ionized. 4. Most of the salts like NaCl, KCl, NaNO3, BaCl2 and mineral acids like HCl, H2SO4, HNO3 and NaOH, KOH etc are common examples of strong electrolytes |
1. These have much lower conductivities at high concentration. 2. λ°m values increase sharply with dilution. 3. Degree of ionisation is very low at high concentration and increases with dilution. 4. Salts like ammonium acetate, acetic acid, aq NH4OH, aqueous CO2 and organic acids and bases are common examples of weak electrolytes. |
Standard half-cell potential E° : If the ionic species have concentration of mol dm–3and pressure of the gaseous species is 1 atm (101.325 KPa), than half-cell potential is called as standard half-cell potential. The temperature being 298 K.
Absolute value of half-cell potential cannot be determined experimentally. However, its value relative to reference electrode can be determined.
Reference electrode 11 given half-cell. E°cell can be measured experimentally using a potentiometer.
Knowing the standard reduction potential of the reference electrode E°half-cell can be found out.