Anode and Cathode Definitions Depend On Charge and Discharge
Michael Faraday defined the cathode as the electrode to which cations (positively charged ions, like silver ions Ag+
) flow, to be reduced by reacting with electrons (negatively charged) from that electrode.
Likewise he defined the anode as the electrode to which anions (negatively charged ions, like chloride ions Cl−
) flow, to be oxidized by depositing electrons on the electrode., it flows in the external circuit.
To an external wire connected to the electrodes of a Galvanic cell (or battery), forming an electric circuit, the cathode is positive and the anode is negative. Thus positive electric current flows from the cathode to the anode through the external circuit in the case of a Galvanic cell.
Consider two voltaic cells, A and B, with the voltage of A greater than the voltage of B. Mark the positive and negative electrodes as cathode and anode, respectively. Place them in a circuit with anode near anode and cathode near cathode, so the cells will tend to drive current in opposite directions. The cell with the larger voltage discharges, making it a voltaic cell. Likewise the cell with the smaller voltage charges, making it an electrolytic cell. For the electrolytic cell, the external markings of anode and cathode are opposite the chemical definition. That is, the electrode marked as anode for discharge acts as the cathode while charging and the electrode marked as cathode acts as the anode while charging.
Read more about this topic: Electrolytic Cell
Famous quotes containing the words definitions, depend, charge and/or discharge:
“Lord Byron is an exceedingly interesting person, and as such is it not to be regretted that he is a slave to the vilest and most vulgar prejudices, and as mad as the winds?
There have been many definitions of beauty in art. What is it? Beauty is what the untrained eyes consider abominable.”
—Edmond De Goncourt (18221896)
“It is better to have the power of self-protection than to depend on any man, whether he be the Governor in his chair of State, or the hunted outlaw wandering through the night, hungry and cold and with murder in his heart.”
—Lillie Devereux Blake (18351913)
“It is hereby earnestly proposed that the USA would be much better off if that big, sprawling, incoherent, shapeless, slobbering civic idiot in the family of American communities, the City of Los Angeles, could be declared incompetent and placed in charge of a guardian like any individual mental defective.”
—Westbrook Pegler (18941969)
“No officer should be required or permitted to take part in the management of political organizations, caucuses, conventions, or election campaigns. Their right to vote and to express their views on public questions, either orally or through the press, is not denied, provided it does not interfere with the discharge of their official duties. No assessment for political purposes on officers or subordinates should be allowed.”
—Rutherford Birchard Hayes (18221893)