the first law of thermodynamics as the statement "in a process at constant pressure, the heat used to produce expansion is universally interconvertible with work" was developed by julius robert von mayer.
the first law of thermodynamics as the statement "in a process at constant pressure, the heat used to produce expansion is universally interconvertible with work" was developed by julius robert von mayer.
the first law of thermodynamics as the statement "in a process at constant pressure, the heat used to produce expansion is universally interconvertible with work" was developed by?
julius robert von mayer
in 1840, germain hess stated a conservation law for the so-called 'heat of reaction' for chemical reactions. his law was later recognized as a consequence of the first law of thermodynamics, but hess's statement was not explicitly concerned with the relation between energy exchanges by heat and work.









































according to truesdell (1980), julius robert von mayer in 1841 made a statement that meant that "in a process at constant pressure, the heat used to produce expansion is universally interconvertible with work", but this is not a general statement of the first law.









































section::::history.:original statements: the "thermodynamic approach".
first law of thermodynamics
section::::definition.:heat capacities for a homogeneous system undergoing different thermodynamic processes.









































section::::definition.:heat capacities for a homogeneous system undergoing different thermodynamic processes.:at constant pressure(isobaric process):.









































at constant pressure, heat supplied to the system would contribute to both the work done and the change in internal energy, according to the first law of thermodynamics. the heat capacity would be called formula_8 . 









































section::::definition.:heat capacities for a homogeneous system undergoing different thermodynamic processes.:at constant volume(isochoric process):.
heat capacity