Terms and Definitions

• thermodynamics is the branch of physics that deals with the conversions, from one to another, of various forms of energy and how these affect temperature, pressure, volume, mechanical action, and work.
• thermodynamics was coined by James Prescott Joule in 1849
• nicolas sadi carnot is the father of thermodynamics
• phase of substance

  1. solid
  2. subcooled solid
  3. saturated liquid
  4. liquid vapor mixture
  5. saturated vapor
  6. ideal gas
  7. real gas
  8. gas mixture
  9. vapor/gas mixture
• IDEALGAS


  in this phase the gas (a highly superheated vapor) behaves in accordance with the ideal gas law.
• REALGAS


  in this phase the gas does not behave in accordance with the ideal gas law.
• GASMIXTURES


  in this phase two or more gases mixed together freely
• VAPOR/GASMIXTURES


  in this phase two or more gases mixed freely with vapor.
• SOLID


  in this phase the substance does not take the shape of the container.
• SUBCOOLED LIQUID

  in this phase the liquid is non-saturated. Non-saturated means that it is not at its boiling point.
• SATURATED LIQUID


  in this phase the liquid can absorb as much heat as it can without vaporizing.
• LIQUID-VAPOR MIXTURE


  in this phase the liquid and vapor co-exist with the same temperature and pressure.
• SATURATED VAPOR


  in this phase the vapor has absorbed more heat than necessary to vaporize it.
• REAL GAS

  Does not meet the above conditions (including Kinetic Molecular Theory).
• REAL GAS


  At laboratory pressure and temperature, they tend to behave like ideal gas.
• IDEAL GAS


  Follows the gas laws at all conditions of temperature and pressure.
• IDEAL GAS


  Abides by the Kinetic-Molecular Theory.
• IDEAL GAS


  Gas particles should occupy zero volume and not exhibit any attractive forces.
• IDEAL GAS


  Does not exist in real world.
• KINETIC MOLECULAR THEORY


  Gases are composed of a large number of particles that behave like hard, spherical objects in a state of constant, random motion.
• KINETIC MOLECULAR THEORY


  These particles move in a straight line until they collide with another particle or the walls of the container.
• KINETIC MOLECULAR THEORY


  These particles are much smaller than the distance between particles. Most of the volume of a gas is therefore empty space.
• KINETIC MOLECULAR THEORY


  There is no force of attraction between gas particles or between the particles and the walls of the container
• KINETIC MOLECULAR THEORY


  Collisions between gas particles or collisions with the walls of the container are perfectly elastic. None of the energy of a gas particle is lost when it collides with another particle or with the walls of the container.
• KINETIC MOLECULAR THEORY


  The average kinetic energy of a collection of gas particles depends on the temperature of the gas and nothing else.
• THERMODYNAMIC SYSTEM


  or simply a system refers to a definite quantity of matter most often contained within some closed surface chosen for study.
• SURROUNDING also called ENVIRONMENT


  is the mass or region outside the system.
• BOUNDARY


  is the real or imaginary surface that separates the system from its surroundings. It can be either fixed or movable. This is where most interaction of energy happens.
• OPEN SYSTEM


  also known as Control volume is a system in which mass is allowed to cross the boundary. Heat, work, and matter can cross the boundary.
• STEADY FLOW SYSTEM


  is a type of open system wherein matter enters and leaves at the same rate. Examples: Boilers, turbines.
• CLOSED SYSTEM


  also known as control mass is a system consisting of a fixed amount of mass, and no mass can cross its boundary. That is, no mass can enter or leave a closed system. However, energy in the form of heat or work, can cross the boundary.
• ISOLATED SYSTEM


  is a system in which neither mass nor energy is allowed to cross the boundary.
• DIATHERMIC SYSTEM is the term if energy crosses the system boundaries
• PROPERTY

  is any quantity, which serves to describe a system. It can be divided into two general types
• INTENSIVE PROPERTY


  is one, which does not depend on the mass of the system such as temperature, pressure, and velocity.
• EXTENSIVE PROPERTY


  is one, which depends on the mass of the system such as volume, and kinetic energy.
• STATE OF SYSTEM


  is its condition as described by giving values to its properties at a particular instant. At a given state, all properties of a system have fixed values. If the value of even one property changes, the state of the system will change to a different one.
• EQUILIBRIUM


  implies a state of balance.
• EQUILIBRIUM


  there are no unbalanced potentials or driving forces within the system.
• A system in equilibrium experiences no changes when it is isolated from its surroundings.