def H(compound_string, T, mass=<NUM_LIT:1.0>):
formula, phase = _split_compound_string_(compound_string)<EOL>TK = T + <NUM_LIT><EOL>compound = compounds[formula]<EOL>result = compound.H(phase, TK)<EOL>return _finalise_result_(compound, result, mass)<EOL>
Calculate the enthalpy of the compound for the specified temperature and
mass.

:param compound_string: Formula and phase of chemical compound, e.g.
  'Fe2O3[S1]'.
:param T: [°C] temperature
:param mass: [kg]

:returns: [kWh] Enthalpy.