(i)State why heat changes in physical and chemical processes are indicated by enthalpy changes and not by entropy changes? (ii)What are the limitations of First Law of thermodynamics?

(i)State why heat changes in physical and chemical processes are indicated by enthalpy changes and not by entropy changes? (ii)What are the limitations of First Law of thermodynamics?
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1 Answer

Answer :

(i) Most of the processes are carried out in an open system i.e, at constant pressure.
 (ii)(a) Can’t explain the feasibility of the reaction.
(b)It poses no restriction on the direction of flow of heat.
(c)Practically it is not possible to convert the heat energy into an equivalent amount of work.
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