The molar heat capacity of ethane is represented in the temperature range 298 K to 400 K by the empirical expression Cp,m/(J K^-1 mol^-1)= 14.73 + 0.1272 (T/K). The corresponding expressions for C(s) and H2(g) are given in table 2.2. Calculate the standard enthalpy of formation of ethane at 350 K from its value at 298 K.