EC - Intro

Redox Applications

  • Redox application aka Electrochem

    • Focus on electron transfer reactions.

    • Key in various technological and scientific applications.

Review Exercise

  • Experiment Overview: A student tested 12.50 g strips of four metals (Ag, Cu, Pb, Mg) in 1.00 mol/L HCl.

  • Observation: One metal reacted vigorously; weigh the reacted metal.

  • Mass of metal that reacted: ______ g (to be recorded to three significant figures).

Fundamental Concepts in Electrochemistry

  • Electrochemistry: The science of electron transfer, focusing on reactions that involve the transfer of electrons.

  • Technological Applications: Important applications include:

    • Electric cells and batteries.

    • Recharging batteries.

    • Fuel cells.

    • Corrosion protection and reversal.

    • Electrolysis and electroplating.

    • Metal refining and purification.

    • Electric cars.

Common Electrical Terminology

  • Electrical Potential Difference (Voltage):

    • Definition: Difference in potential energy per coulomb of charge between anode and cathode.

    • Change in energy: Measured in joules per coulomb (J/C).

    • Analogy: An electron's "desire" to move from anode to cathode.

    • Symbol: V; Unit: Volt (named after Alessandro Volta); measured with a voltmeter.

The History of Electricity and Volta

  • Luigi Galvani

    • Discovered the connection between electricity and muscle movement in frogs in the late 1780s.

  • Alessandro Volta

    • In 1792, concluded that animal electricity was not needed; the movement was due to normal electrical effects.

    • Noted metals needed to be different to create movement in experiments with frogs.

  • Electromotive Force:

    • Volta categorized metals by their electromotive force, leading to the early understanding of electrode potentials.

    • Metals like silver and zinc showed the strongest effects.

Notable Volta Experimentations

  • Volta noted experiencing a shock when connecting metal rods from his apparatus to his ears, indicating the effects of electricity on human sensation.

Electrical Charge and Current

  • Charge:

    • Quantity of energy measured in coulombs.

    • Symbol: q; Unit: C (coulomb); where 1 C = 1 ampere × second.

  • Current:

    • Flow of electrons past a point in a circuit per second.

    • Analogy: likened to river current.

    • Symbol: I; Unit: A (ampere); measured with an ammeter.

  • Power:

    • Both voltage and current contribute to power, given by the formula: P = IV.

    • Importance: Both proper voltage and current are essential to run electrical devices (example: beercan battery lab).

Water Analogy for Electrical Concepts

  • Analogy Breakdown:

    • Charge = water.

    • Voltage = pressure of water.

    • Current = flow of the water.

    • Power = total amount of water flowing over time.