Concepts of enthalpy and internal energy

Replies

• 

  ISHAN TOPRE

  Hi shehbaz,
  Internal energy is energy arising in the form of motions of molecules.The energy is manifested as translational,rotational and vibrational movements of molecules.
  This form of energy depends generally on the temperature and measured above a certain temperature reference.
  it is denoted by 'U' where dU=m*(sp.heat at const volume)*dT
  in other words whenever you are boiling water,you are adding heat hence tempereture increases.To measure the amount of heat added in atoms and molecules the term internal energy is used.
  Now enthalpy is denoted by 'h' where h=u+pv;
  here p*v is nothing but work done in a process.
  we can say that enthapy is sum of internal energy and work done in a process.
  Now coming to your question,just look at the terms involved in these equations.and if You find any term missing,go through any reference book for indepth derivation.😀
• 

  shehbaz

  While going through derivations to determine internal energy,I came to know that U is dependent upon volume(v) & temperature(t)i.e. U=U(V,T),,,now if I see enthaply(H)
  ,,it is given as H=U + PV,,,
  on RHS:-
  U= U(V,T) &
  P=P(V,T) -->from characteristic gas equation.
  so, from this I can say that H is function of V and T,,
  Now my Q which arises by looking above inter-relation," is both U & H functions of V & T ? ".
  if yes then y H is said to be the function of P & T
  Thks for the reply sir.