Energy L2 Nader

Energy L2 Nader

1. Intro

   • "Capability to generate an effect"
   • Energy can be stored within a system and can be transferred from one another
   • In thermodynamics we are interested in transport and conversion of energy

2. Microscopic view

   • Or statistical thermodynamics, the transport of energy is analysed from a molecular point of view
   • 3 general forms of energy
     • 1. Molecular kinetic energy: translational velocity of individual molecules
     • 2. Intramolecular energy: (within the individual molecules) associated with molecular and atomic structure and related forces
     • 3. Intermolecular potential energy: associated with the forces btw the molecules
   • In most gases at usual pressure and tmp, the distances btw molecules are large compared to size of molecule>> intermolecular force are negligible
   • mechanisms for the storage of microscopic energy in gases
     • A) Molecular Translation: Kinetic energy due to the translation of the molecule
     • B) Molecular Rotation: Molecule can rotate around an axis
     • C) Molecular Vibration: Atomic bonds can stretch and result in molecular vibration
     • D) Electron translation: Rotation of electrons around the nucleus
     • Energy stores in the gas is the sum of all these models of energy storage

3. Microscopic view

   • In classical thermodynamics we ssume that matter is a CONTINUUM, which means molecules and atoms are ignored and replace by a continuous medium
     • Change in system properties
   • A) PRESSURE (force/area)
     • Units
     • Absolute pressure: zero-referenced against a perfect vacuum, so it is equal to gauge pressure plus atmospheric pressure.
     • gauge pressure: difference btw absolute and atmospheric pressure existing at the gauge
       • use manometer (contains water, mercury, alcohol, oil or another