Question

Calculate the standard enthalpy change for the reaction where 3 moles of hydrogen gas react with 1 mole of nitrogen gas to form 2 moles of ammonia gas. Given the following thermochemical equation: N2(g) + 3 H2(g) → 2 NH3(g)    ΔH° = −92.4 kJ/mol

Answer 1

The given thermochemical equation is already balanced and represents the reaction of 3 moles of hydrogen gas with 1 mole of nitrogen gas to form 2 moles of ammonia gas:N2 g  + 3 H2 g   2 NH3 g     H = 92.4 kJ/molSince the reaction is already balanced and the moles of reactants are given, the standard enthalpy change for this reaction is simply the value provided:H = 92.4 kJ/mol