The correct statement that describes the two types of reactions that occur in operating electrochemical cells is:
"Spontaneous reactions occur in voltaic cells, and nonspontaneous reactions occur in electrolytic cells."
Let's break it down to understand:
1. Voltaic cells (also known as galvanic cells) are spontaneous chemical reactions that produce electrical energy. These reactions occur without any external assistance and convert chemical energy into electrical energy. Example: A battery powering a flashlight is a voltaic cell.
2. Electrolytic cells are nonspontaneous reactions that require an external electrical current to drive the reaction. These cells use electrical energy to cause a chemical change. Example: Electrolysis of water to produce hydrogen and oxygen gas.
By understanding this distinction, we can see that in voltaic cells, the spontaneous reactions generate electrical energy, while in electrolytic cells, nonspontaneous reactions require external energy to drive the process.
