Question

Why is cathode in an electrolytic cell considered to be negative and anode positive?

Answer 1

Hint: Electrode is a substance which helps in the conduction of electricity in which the electric current enters or leaves the non-metallic medium as in electrolytic cells. Electrodes generally consist of anode and cathode which basically describe the direction of flow of current.

Complete Solution :
- Electrolytic cell also known by the name electrochemical cell which is defined as an electrochemical device which uses electrical energy to facilitate non-spontaneous redox reactions. The main three primary components of electrolytic cells are: Anode, Cathode and Electrolyte.
- Cathode is said to be electrolyte where reduction occurs. Cathode is considered as negative because the supplied electrical energy to the cell results in the decomposition of chemical compounds. But in the case of galvanic cells it can also be positive because in this case chemical reaction leads to the generation of electrical energy.
- An anode in an electrochemistry can be defined as that electrode where oxidation reaction occurs. Generally at an anode negative ions known as anions are present. If we take a galvanic cell the anode is negative in nature and the electrons mostly move towards the external part of the circuit and in an electrolytic cell it is positive in nature.
Hence we can consider why cathode in an electrolytic cell is considered to be negative and anode positive.

Note: Anode generally acts as an electron donor and in an electrolytic cell oxidation reactions takes place at the anode while cathode acts as an electron acceptor and in case of electrolytic cell reduction reactions take place at cathode.