Question

What is the standard enthalpy of formation of ammonia gas (NH3) at 298 K, given that the standard enthalpy of formation of nitrogen gas (N2) and hydrogen gas (H2) are 0 kJ/mol and 0 kJ/mol, respectively?

Answer 1

The standard enthalpy of formation of ammonia gas  NH3  at 298 K is -46.11 kJ/mol. This value is found in standard thermodynamic tables and represents the enthalpy change when one mole of ammonia is formed from its constituent elements, nitrogen gas  N2  and hydrogen gas  H2 , under standard conditions  298 K and 1 atm pressure .