6.13 Given .What is the standard enthalpy of formation of gas?
the standard enthalpy of formation of any compound is the required change in enthalpy of formation of 1 mole of a substance in its standard form from its constituent elements.
Thus we can re-write the reaction as;
Therefore, standard enthalpy of formation of ammonia is =
= 1/2 (-92.4)
= -46.2 kJ/mol