Katodereaksjonen

Katodereaksjonen, also known as the cathode reaction, is a fundamental concept in electrochemistry, which is the branch of chemistry that deals with the interconversion of chemical and electrical energy. It refers to the half-reaction that occurs at the cathode during an electrochemical process, such as in a galvanic cell or an electrolytic cell.

In a galvanic cell, which is an electrochemical cell that converts chemical energy into electrical energy, the cathode is the positive electrode where reduction occurs. The katodereaksjonen involves the gain of electrons by a chemical species, leading to its reduction. For example, in a zinc-copper galvanic cell, the cathode is made of copper, and the katodereaksjonen is the reduction of copper ions (Cu²⁺) to copper metal (Cu) with the gain of two electrons.

In an electrolytic cell, which is an electrochemical cell that uses electrical energy to drive a non-spontaneous chemical reaction, the cathode is the negative electrode where reduction still occurs. The katodereaksjonen in this context involves the reduction of positively charged ions, or cations, present in the electrolyte solution. For instance, in the electrolysis of molten sodium chloride, the katodereaksjonen is the reduction of sodium ions (Na⁺) to sodium metal (Na) with the gain of one electron.

The katodereaksjonen is a crucial aspect of understanding and predicting the behavior of electrochemical systems. It is governed by the principles of oxidation and reduction, and its study is essential in various fields, including energy storage, corrosion science, and electroplating.