Electrolysis

• electrolysis (אלקטרוליזה)

• electrolyte (אלקטרוליט)

  • “A substance that produces ions when dissolved in water; its solution conducts electricity.” (Timberlake, 2017)
  • “a substance that conducts electricity through the movement of ions, but not through the movement of electrons” (Wikipedia)
  • strong electrolyte
  • weak electrolyte

• nonelectrolyte

  • ”A substance that dissolves in water as molecules; its solution does not conduct an electrical current.” (Timberlake, 2017)

• electrolyte identificationtodo

  • soluble ionic compound → strong electrolyte
  • covalent compound
    • ionize completely in water → strong electrolyte
    • ionize partially in water → weak electrolyte
    • not ionize in water → non-electrolytes

Electrochemical cell

• electrochemical cell (תא אלקטרוכימי)
  • electrolytic cell
  • galvanic cell (or voltaic cell) is an electrochemical cell that converts chemical energy into electrical energy
  • fuel cell
• electrode: conductor through which electric current enters or leaves the cell
  • anode ($-$): the electrode where oxidation occurs
  • cathode ($+$): the electrode where reduction occurs
  • the part of each electrode outside the solution is called the terminal which is used to connect the cell to a circuit
• salt bridge (or ion bridge)

Examples

• (Daniell cell)
  • $\underset{\mathrm{Anode}}{\mathrm{Zn}{}^{\circ }(\mathrm{s})}|\mathrm{Zn}{}^{2+}(\mathrm{aq})||\mathrm{Cu}{}^{2+}(\mathrm{aq})|\underset{\mathrm{Cathode}}{\mathrm{Cu}{}^{\circ }(\mathrm{s})}$
  • net ionic eq.: $\mathrm{Zn}(\mathrm{s})+\mathrm{Cu}{}^{2+}(\mathrm{aq})\to \mathrm{Zn}{}^{2+}(\mathrm{aq})+\mathrm{Cu}(\mathrm{s})$
  • Solfate example:
    • $\mathrm{Zn}{}^{\circ }(\mathrm{s})|\underset{\mathrm{Anolyte}}{\mathrm{ZnSO}{}_4(\mathrm{aq})}||\underset{\mathrm{Catholyte}}{\mathrm{CuSO}{}_4(\mathrm{aq})}|\mathrm{Cu}{}^{\circ }(\mathrm{s})$, or in different notation,
    • $\mathrm{Zn}{}^{\circ }(\mathrm{s})|\mathrm{Zn}{}^{2+},\underset{\begin{array}{c}\text{Spectator}\\ \text{ion}\end{array}}{\mathrm{SO}{}_4{}^{2-}}||\underset{\begin{array}{c}\text{Spectator}\\ \text{ion}\end{array}}{\mathrm{SO}{}_4{}^{2-}},\mathrm{Cu}{}^{2+}|\mathrm{Cu}{}^{\circ }(\mathrm{s})$
• $\mathrm{Cu}(\mathrm{s})|\mathrm{Cu}{}^{2+}(\mathrm{aq})||\mathrm{Ag}{}^{+}(\mathrm{aq})|\mathrm{Ag}(\mathrm{s})$
  • $\mathrm{Cu}{}^{\circ }(\mathrm{s})|\mathrm{Cu}(\mathrm{NO}{}_3){}_2(\mathrm{aq})||\mathrm{AgNO}{}_3(\mathrm{aq})|\mathrm{Ag}{}^{\circ }(\mathrm{s})$

Battery

• A battery is a collection of electric cells connected together

• primary cell (or primary battery)

• secondary cell (or rechargeable battery, storage battery) 

• dry cell

• half-cell

• standard electrode potential

• volatge regulator

• State of charge (SoC)

• State of health (SoH)

• battery management system (BMS)

References

• Timberlake, Karen C. (2017). Chemistry: An Introduction to General, Organic, and Biological Chemistry. Pearson.