Final answer:
An electrolytic cell uses electrical energy to drive chemical reactions and has a positive anode and a negative cathode, opposite to a voltaic cell. Electroplating and electrolysis are typical applications of such cells. In electrochemical reactions like those in a lead-acid battery, sufficient voltage is required to promote the nonspontaneous reaction.
Step-by-step explanation:
Understanding Electrolytic Cells
An electrolytic cell is an apparatus for conducting electrochemical reactions, wherein electrical energy is converted into chemical energy. Unlike a voltaic cell, an electrolytic cell is used to drive a nonspontaneous reaction through an external voltage source such as a battery. It consists of two electrodes, the anode and the cathode, submerged in an electrolyte solution, connected by a conductive wire and often a salt bridge.
In an electrolytic cell, by convention, the anode is the positively charged electrode connected to the positive terminal of the battery, while the cathode is negatively charged and connected to the negative terminal. This is the reverse of a voltaic cell. The flow of electrons is from the anode to the cathode externally, driving the redox reactions within the cell.
Oxidation occurs at the anode, with atoms or molecules losing electrons. Reduction occurs at the cathode, where atoms or molecules gain electrons. Electroplating and electrolysis are examples of applications for electrolytic cells. Electroplating uses the cell to coat an object with a metal layer by making it the cathode, thereby depositing metal ions onto it. Electrolysis separates substances through the induced chemical reactions, such as splitting water into hydrogen and oxygen gases.
For a reaction in an electrolytic cell to occur, such as in the lead-acid battery, the battery must provide sufficient voltage to overcome the negative standard cell potential, indicating the process is nonspontaneous. Lead-acid batteries, common in vehicles, employ lead plates at the anode and lead oxide plates at the cathode, with sulfuric acid as the electrolyte that participates in the charge-conducting chemical reaction.