Explain the principle involved in an electrochemical cell.

An electrochemical cell is a device that generates electrical energy (or voltage) through a redox reaction. A redox reaction consists of two half-reactions: oxidation and reduction. Oxidation is the process of losing electrons, while reduction is the process of gaining electrons. The two half-reactions together describe the flow of electrons from one species to another. In an electrochemical cell, these half-reactions happen in separate compartments called half-cells.

An electrochemical cell consists of the following components: 1. Two electrodes: The electrodes are conductive materials (usually metals) where the redox reactions occur. 2. Two half-cells: These compartments contain the substances undergoing the redox reaction and are connected through a migration of ions. Each half-cell has an electrode and an electrolyte. 3. Electrolytes: The electrolytes are the solutions containing the ions of the reactants and products involved in the redox reaction. 4. Salt bridge: This is a pathway that allows ions to move between the two half-cells, maintaining a neutral charge balance.

An electrochemical cell works through the following steps: 1. Oxidation occurs at the anode (the electrode where oxidation takes place) and causes the loss of electrons. These electrons flow through an external electrical circuit, producing an electric current. 2. Reduction occurs at the cathode (the electrode where reduction takes place). This process involves gaining electrons to form a reduced product. 3. The flow of electrons creates a difference in electric potential (or voltage) between the two electrodes, which can be harnessed to do work. 4. The movement of electrons is accompanied by the movement of ions through the electrolytes and the salt bridge. This maintains charge neutrality and helps to sustain the redox reaction, allowing the cell to continue producing an electrical current. So, to summarize, the principle involved in an electrochemical cell is the conversion of chemical energy into electrical energy through a redox reaction. This reaction takes place in two separate half-cells, with electrons flowing through an external circuit and ions moving through the electrolytes and salt bridge.