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.