ANS:C - equivalent mass of the electrolyte.

Faraday's law of electrolysis is related to the equivalent mass of the electrolyte. Faraday's laws of electrolysis describe the quantitative relationship between the amount of substance produced or consumed in an electrolytic reaction and the amount of electric charge passed through the electrolyte. Specifically, the laws state:

1. The mass of a substance deposited or liberated at an electrode during electrolysis is directly proportional to the quantity of electricity (in coulombs) passed through the electrolyte.
2. The mass of different substances deposited or liberated by the same quantity of electricity is proportional to their respective chemical equivalent masses.

The chemical equivalent mass of an electrolyte is related to its molar mass and the number of electrons involved in the electrochemical reaction. It represents the mass of the substance that reacts with one mole of electrons transferred in the electrolysis process. Faraday's law is not directly related to the cation speed or the atomic number of the cation. Therefore, the correct answer is: equivalent mass of the electrolyte.