Electrical Engineering ⇒ Topic : Relation Between E and Z
Relation Between E and Z
Suppose the same amount of charge (Q) is passed through the solutions of two electrolytes. If m1 and m2 are the masses of the substances liberated/deposited and Z1 and Z2 are their electro-chemical equivalents, then
Thus the ratio EIZ is the same for all substances. This constant is called Faraday constant F(=E/Z).
Faraday constant (F). The value of Faraday constant is found to be 96500 C i.e. F = 96500 C.
Hence Faraday constant is the quantity of charge (i.e., 96500 C) required to liberate/deposit one gram equivalent (chemical equivalent in gram) of the substance during electrolysis.
For example, chemical equivalent of silver is 108. When a charge of 96500 C is passed through a silver voltameter, then mass of silver deposited on the cathode will be 108g. Again chemical equivalent of copper is 31.75. If a charge of 96500 C is passed through a copper voltameter, then mass of copper deposited on the cathode will be 31.75 g.
Finding the value of E According to Faraday's first law of electrolysis,
m = ZQ
Suppose M is the mass of one mole of the substance. If, during electrolysis, the mass of the substance to be deposited is M and p is the valency of the depositing atom, then NA (= 6.023 x 1023) atoms will deposit on the electrode.
!! OOPS Login [Click here] is required for more results / answer