What is electrolysis?

• A. The process of heating a solution
• B. The process of electrically inducing chemical changes in a solution
• C. The process of filtering a solution
• D. The process of evaporating a solution

Answer: (B)

Electrolysis is using electrical energy to drive chemical changes that wouldn’t happen on their own. In an electrolyte, an external power source pushes ions to move to the electrodes: positive ions travel to the cathode and gain electrons (reduction), while negative ions go to the anode and lose electrons (oxidation). This forced transfer of electrons causes the compound in the solution to decompose or new substances to form, such as splitting water into hydrogen and oxygen or depositing metal onto a surface.

The other processes are different: heating changes temperature, not the chemical bonds via electric energy; filtering simply separates substances by size or state; evaporating removes solvent by turning it into vapor.