Question

2. There exists a form of energy, known as internal energy U, which is an intrinsic property of a system, functionally related to the measureable coordinates which characterize the system. Write the formula to describe changes in this property for a closed system, not in motion. Describe the concept of internal energy. What is the energy source of the internal energy? Does it change along with the process?

Answer 1

Internal erozga (0) Change in internal crocoy U in a closed system is equal to head trasfoored if the reversible process takes place at com From Ist law of thermodynamics are know, 19 = 40 +W wananaw , 18 any heat tocamper. W=- Pdv and for constant vallume dvo, : 4W=0. TAU = 48 KA closed system can eachonge mugy but not matter with its clonourdin The concept of internal energy Focom Ist lawcy Thormodynamics ** *w. 9=40+W Although q (head toonder) and w [Clonk clone) are path fenebron ie depends upon path, their sum Change in intumal energy (40) is independent of path hence so =state function. Internal energy is defined as the energy which is associated with random disordered motion associated with the molecules Intemal energy say about inutible microscopic en the atomic and molecular scale It is or the onergy cechich ceckich 0 dremain a in system, encleeding kinetic and potential enorgy of system as a whole due to external force V fields. Internal energy of a system incuares cochen heat is colded, and deocases weken oyslem doescesork. © At absalute you internal energy becomes zero', but deceto pource of quantum mechanical effect, a firule zero point cowgy always exists. 7 Errorgy source of internal energy Intermal energy is the aim of Polentail energy and kinote слеgi assoc. enegy associated curth the system to liquid on en potential energ is associated with в ае intermolecular attractive forces.

Thuo tumo/alional Kinetic energy, vibralional and rotaliond binolie energy and polentiâl mergy from inter molecular fonces are ocesponsible to be a source af internalenoidy Does internal energy changes along weeth the proces - To occuce some changes of internal enanigry there should be a change in temporalew fon am edeal gev. Als wecknow AU- nē (Ta-T). .. Change in internal energy oo ( change in temperatwa). If there is no change in tempo alivie , there is no change in internel. crogy: # the system is isolated re neither heat an non grass is passed, the interno energy can't change as a resuelt.