What is an electrolytic cell? Solution: An electrolytic cell is a type of cell that uses electrical energy to drive a non-spontaneous redox reaction.
- How does an electrolytic cell differ from a galvanic cell? Solution: An electrolytic cell requires an external power source to drive the non-spontaneous redox reaction, while a galvanic cell generates an electric current from a spontaneous redox reaction.
- What happens at the anode in an electrolytic cell? Solution: At the anode of an electrolytic cell, oxidation occurs – this is where electrons are lost.
- What happens at the cathode in an electrolytic cell? Solution: At the cathode of an electrolytic cell, reduction occurs – this is where electrons are gained.
- What is electrolysis? Solution: Electrolysis is the process of driving a chemical reaction through the application of an external electric current.
- How does the electrolysis of water work? Solution: When an electric current is passed through water, it decomposes into hydrogen gas and oxygen gas. This process is an example of electrolysis.
- What is the role of the salt bridge in an electrolytic cell? Solution: In an electrolytic cell, a salt bridge is not necessary as the ions are provided by the electrolyte itself.
- What is Faraday’s First Law of Electrolysis? Solution: Faraday’s First Law states that the amount of substance deposited or dissolved at an electrode is directly proportional to the quantity of electricity passed.
- What is Faraday’s Second Law of Electrolysis? Solution: Faraday’s Second Law states that the amounts of different substances liberated by the same quantity of electricity passing through the electrolytic solution are proportional to their equivalent weights.
- What factors affect the amount of product formed in an electrolytic cell? Solution: The amount of product formed in an electrolytic cell is influenced by the amount of electricity used (current x time) and the stoichiometry of the reaction.
- How can electrolysis be used in electroplating? Solution: Electroplating is a process that uses electrolysis to deposit a layer of metal onto a surface. The object to be plated is placed at the cathode and the metal to be plated is placed at the anode. When current is applied, metal cations from the anode are reduced at the cathode to form a thin layer of metal.
- How is electrolysis used in the refining of metals? Solution: Electrolysis is used in the refining of metals to separate pure metal from impurities. The impure metal is made the anode and pure metal is made the cathode. On passing current, the impure metal dissolves and the pure metal is deposited at the cathode.
- How can the efficiency of an electrolytic cell be increased? Solution: Efficiency of an electrolytic cell can be increased by optimizing conditions such as the concentration of the electrolyte, temperature, and the applied current.
- Why is heat produced in an electrolytic cell? Solution: Heat is produced in an electrolytic cell due to the resistance to the flow of current in the electrolyte and in the electrodes. This is a form of energy loss.
- How is electrolysis used in the production of chlorine and sodium hydroxide? Solution: Electrolysis is used to produce chlorine and sodium hydroxide from a solution of sodium chloride. At the anode, chloride ions are oxidized to produce chlorine gas. At the cathode, water is reduced to produce hydrogen gas and hydroxide ions.
- Why must the electrolyte in an electrolytic cell be an ionic compound? Solution: An ionic compound is needed in an electrolytic cell to facilitate the movement of ions. This allows for the transfer of charge, which is necessary for the redox reaction to occur.
- How does the nature of the electrodes affect the electrolysis process? Solution: The nature of the electrodes can influence the potential at which the electrolysis reactions occur. For example, inert electrodes like platinum do not participate in the reaction, while others such as copper can dissolve into the electrolyte.
- What is overpotential and how does it affect electrolysis? Solution: Overpotential is the extra voltage required to make a reaction happen at an electrode in an electrolytic cell, over and above the standard electrode potential. It can affect the efficiency of electrolysis as more energy is required to drive the reaction.
- Why are some electrolytic cells divided into separate compartments? Solution: Some electrolytic cells are divided into separate compartments to prevent the products of electrolysis from reacting with each other.
How is electrolysis used in the production of aluminum? Solution: The production of aluminum involves the electrolysis of molten aluminum oxide. Aluminum ions are reduced at the cathode to form aluminum metal, while oxygen is formed at the anode.