Cells and batteries

• What is an electrochemical cell made up of?


  Two different electrodes and an electrolyte
• Why must the electrodes in an electrochemical cell be able to conduct electricity?


  Because they need to facilitate the flow of electric charge
• What is the role of the electrolyte in an electrochemical cell?


  It is a liquid that contains ions which react with the electrodes
• What happens when the electrodes and electrolyte react in a cell?


  A charge difference is set up between the electrodes
• What occurs when the electrodes of an electrochemical cell are connected by a wire?


  Electricity is produced as the charge flows
• How can the voltage of a cell be measured?

  By connecting a voltmeter to the circuit
• What factors affect the voltage of a cell?

  The type of electrodes and the electrolyte used
• How does the reactivity of electrodes influence the voltage of a cell?


  A bigger difference in reactivity leads to a bigger voltage
• How can you predict the voltage of a cell?


  From information about the voltages of other cells
• If Electrode A is lead and Electrode B is tin, what is the voltage of the cell?


  +0.01V
• What does a negative voltage indicate about the reactivity of electrodes?


  It indicates that one electrode is more reactive than the other
• What happens to the reactants in non-rechargeable batteries over time?


  They get used up and turned into products
• Why can't non-rechargeable batteries be recharged?


  Because the products aren't turned back into reactants
• What type of reactions do non-rechargeable batteries, like alkaline batteries, use?


  Irreversible reactions
• How can rechargeable cells be recharged?


  By connecting them to an external electric current
• What is the process of determining the order of reactivity of metals based on cell voltages?


  • Compare voltages of cells with different electrodes
  • Identify which metal is more reactive based on positive or negative voltage
  • Arrange metals from least to most reactive based on findings
• What should you remember to do in the exam regarding the order of reactivity of metals?


  Use the correct terminology when writing your answer