In which of the following cells, oxidation and reduction takes place in two separate half cells?

Both Option 2 and Option 3

The answer is 4. Both Option 2 and Option 3.

Both electrochemical cells and Daniel cells have oxidation and reduction taking place in two separate half cells.

Electrochemical cells are devices that convert chemical energy into electrical energy. They are made up of two half cells, an anode and a cathode. The anode is where oxidation takes place, and the cathode is where reduction takes place.

Daniel cells are a type of electrochemical cell that uses a zinc anode and a copper cathode. The zinc electrode is oxidized, and the copper electrode is reduced.

In both electrochemical cells and Daniel cells, the oxidation and reduction reactions take place in separate half cells because the electrodes are made of different materials. The different materials have different reduction potentials, which means that they have different tendencies to lose electrons.

The oxidation reaction occurs at the anode, where the electrode loses electrons. The reduction reaction occurs at the cathode, where the electrode gains electrons. The electrons that are lost at the anode are transferred to the cathode, where they are used to reduce the other reactant.

The flow of electrons from the anode to the cathode creates an electric current. This electric current can be used to power devices or to do work.