code: def isentropic_exponent(self):
          r'''Gas-phase ideal-gas isentropic exponent of the chemical at its
          current temperature, [dimensionless]. Does not include
          pressure-compensation from an equation of state.
  
          Examples
          --------
          >>> Chemical('hydrogen').isentropic_exponent
          1.405237786321222
          '''
          Cp, Cv = self.Cpg, self.Cvg
          if all((Cp, Cv)):
              return isentropic_exponent(Cp, Cv)
          return Nonf isentropic_exponent(self):
          r'''Gas-phase ideal-gas isentropic exponent of the chemical at its
          current temperature, [dimensionless]. Does not include
          pressure-compensation from an equation of state.
  
          Examples
          --------
          >>> Chemical('hydrogen').isentropic_exponent
          1.405237786321222
          '''
          Cp, Cv = self.Cpg, self.Cvg
          if all((Cp, Cv)):
              return isentropic_exponent(Cp, Cv)
          return None
docs: r'''Gas-phase ideal-gas isentropic exponent of the chemical at its
          current temperature, [dimensionless]. Does not include
          pressure-compensation from an equation of state.
  
          Examples
          --------
          >>> Chemical('hydrogen').isentropic_exponent
          1.405237786321222