Electrolysis is the process in which electrical energy is converted to chemical energy. In electrolytic cell, oxidation takes place at anode and reduction at cathode. Electrode process depends on the electrode taken for electrolysis. Amount of substance liberated at an electrode is directly propertional to the amount of charge passed through it. The mass of substance liberated at electrode is calculated using the following relation : `m= ("ItE")/(96500)` Here, E represents the equivalent mass and 96500 C is called the Faraday constant. Faraday (96500 C) is the charge of 1 mole electron, i.e., `6.023 xx 10^(23)` electrons, it is used to liberate one gram equivalent of the substance. The passage of current liberates `H_(2)` at cathode and `Cl_(2)` at anode. The solution is :A. copper chloride in waterB. NaCl in waterC. mercuric chloride in waterD. `AuCl_(3)` in water