What is the different b/n internal energy(^E) and enthalpy(^H)? Under what circumstances are internal energy and enthalpy nearly equal?

2 answers

internal energy: stored in bonds and mass.

enthalpy: that portion of internal energy which can be released (or absorbed) during a chemical reaction.
What is the different b/n change in internal energy(^E) and enthalpy change(^H)? Under what circumestance are change in energy(^E) and enthalpy change(^H) nearly equal? Thanks for your helps.