## Lecture 3

 what is a system and surroundings in thermodynamic problems
 a system is the macroscopic body under study, and the surroundings are everything else
 what are the three systems of thermodynamic classification
 open, closed and isolated
 what do open systems do
 open systems exchange both mass and energy with it’s surroundings
 what do closed systems exchange
 closed systems exchange energy but not mass with their surroundings
 what do isolated systems exchange
 isolated systems do not exchange either mass or energy with its surroundings
 what are state functions
 such properties that describe the state of a system
 there are only two ways to transfer energy between systems, what are they
 heat and work
 what is heat
 the natural transfer of energy from a warmer body to a cooler body
 what is work
 any transfer of energy that is not heat
 what are the three forms of heat
 what is conduction
 thermal energy transfer via molecular collisions
 give an example of conduction
 when higher energy molecules transfer some of its energy to lower energy molecules via molecular collision
 what is convection
 differences in pressure and density drive warm fluid to cooler fluid
 thermal energy transfer via electromagnetic waves- when a metal is heated it glows bright orange and then blue- this is electromagnetic waves
 what is Newton’s law of cooling
 the cooling of a body is directly proportional to the temperature difference betweenthe body and its environment
 in constant pressure conditions, how can you calculate the work being done
 w= P delta V
 how can you find the average kinetic energy of a single molecule in any fluid
 3/2 kT
 what is change in enthalpy
 delta H= delta U + PdeltaV
 An element in its standard state at 25 C is arbitrarily assigned
 an enthalpy of 0 J/mol
 for reactions involving no change in pressure, the enthalpy equals
 the enthalpy equals the heat
 when there is an absence of work within a reaction
 the enthalpy is equal to the change in energy
 what is the heat of the reaction
 this is the change in heat from the reactants to products
 what does endothermic mean
 the enthalpy change is positive
 what does exothermic mean
 the enthalpy change is negative
 what sort of chemical state does the activation energy hill represent
 it represents the transitional state
 a catalyst affects the what but not the what
 it affects the rate but not the equilibrium
 what is the term entropy
 this is the tendancy toward disorder
 something with higher entropy has higher
 probability
 what does the second law of thermodynamics state
 that entropy of an isolated sysytem will never decrease
 only reactions equal to zero are considered ideal reactions and only ideal reactions have
 zero change in enthalpy
 what dictates the direction of a reaction
 entropy
 reactions at equilibrium have achieved
 the maximum universal entropy
 when temperature, volume and pressure increase, so does
 entropy
 when is zero entropy applied
 with any pure substance or any molecule at absolute zero
 a negative delta G indicates
 spontaniety
Tagged In :

## Get help with your homework

Haven't found the Essay You Want? Get your custom essay sample For Only \$13.90/page

Sarah from studyhippoHi there, would you like to get such a paper? How about receiving a customized one?

Check it out