Introduction to Electrochemistry

What is Electrochemistry?

• Study of the relationship between chemical reactions and electricity.
• Two main interactions:
  1. Chemical reactions can create electricity (e.g., batteries).
  2. Electricity can induce certain chemical reactions.

Key Concepts

Electricity

• Defined as the movement of electrons.
• Commonly involves electrons moving through wires, light bulbs, batteries, etc.

Chemical Reactions in Electrochemistry

• Involves movement of electrons.
• Focus on oxidation-reduction (redox) reactions.

Interactions Between Chemical Reactions and Electricity

Creating Electricity

• Electrons move between atoms in a redox reaction.
• If separated by a wire, electrons move through the wire, creating electricity.

Inducing Chemical Reactions

• Use electrical energy to force electron movement between atoms.

Examples and Devices

Galvanic/Voltaic Cells

• Device that uses chemical reactions to create electricity.
• Example: Zinc-Copper Galvanic Cell
  • Zinc atoms lose electrons (oxidized) and Cu²⁺ ions gain electrons (reduced).
  • Spontaneous reaction (happens on its own).
  • Electrons travel through a wire, creating electricity.
• Key Terms:
  • Electrodes: Metals involved in the reaction.
  • Anode: Site where oxidation occurs.
  • Cathode: Site where reduction occurs.
• Mnemonic: "An Ox Red Cat"
  • Anode = Oxidation, Cathode = Reduction.

Electrolysis

• Process where electricity is used to induce chemical reactions.
• Uses an electrolytic cell.
• Example: Splitting water into hydrogen and oxygen gases.
  • Non-spontaneous reaction (oxygen doesn't naturally give up electrons).
  • Battery forces electron movement.
• Key Terms:
  • Anode: Site of oxidation (where oxygen loses electrons).
  • Cathode: Site of reduction (where hydrogen gains electrons).

Conclusion

• Electrochemistry examines both spontaneous and non-spontaneous reactions.
• Galvanic cells harness spontaneous reactions to produce electricity.
• Electrolysis uses electrical energy to force non-spontaneous reactions.