Describe the differences between anode and cathode reactions in electrolysis.

In electrolysis, anode and cathode reactions differ in terms of the type of ions involved and the products formed.

The anode reaction involves the oxidation of negatively charged ions, such as chloride (Cl-) or sulphate (SO42-), to form neutral molecules or atoms. For example, at the anode during the electrolysis of sodium chloride (NaCl) solution, chloride ions are oxidised to form chlorine gas (Cl2) and water (H2O) is produced as a by-product. This is known as an oxidation reaction.

On the other hand, the cathode reaction involves the reduction of positively charged ions, such as hydrogen (H+) or metal ions, to form neutral molecules or atoms. For example, at the cathode during the electrolysis of copper (II) sulphate (CuSO4) solution, copper ions (Cu2+) are reduced to form copper metal (Cu) and hydrogen gas (H2) is produced as a by-product. This is known as a reduction reaction.

Overall, the anode and cathode reactions in electrolysis are essential for the separation of different elements or compounds from a solution. The type of ions present and the products formed depend on the specific electrolyte used and the conditions of the electrolysis process.