Question

Calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest kj .

Answer 1

The formation of nitric acid from nitrogen, hydrogen, and oxygen can be written as,

     N₂ + H₂ + 3O₂ --> 2HNO₃

The net enthalpy of formation of nitric acid is calculated by,
   Hrxn = Hproduct - Hreactant

Since all the reactants are in their elemental forms, the simplified equation would be,

    Hrxn = Hproduct 

Substituting,

    Hrxn = (-186.81 kJ/mol)(2 mols)

Answer: -372.42 kJ