EXAMPLE 3.14 For the following reaction the standard heat of reaction at 298 K is -164.987 kJ. CO2 (g) + 4 H2 (9) 2 H20 (g) + CH4 (9) The constants in the heat capacity (J/mol K) equation, Eq. (3.50), are given below: b 9 CO2 26.75 42.26 10-3 - 14.25 10-6 H2 4.35 10-3 -0.33 10-6 H20 29.16 14.49 10-3 -2.02 10-6 CH4 13.41 77.03 D 10-3 - 18.74 10-6 Calculate the standard heat of reaction at 773 K. 26.88