Enthalpy of formation of NH3 is – 46 kJ/kg mole. The enthalpy change for the gaseous reaction, 2NH3 → N2 + 3H2, is equal to _____________ kJ/kg. mole?
Correct answer: D
Explanation
The reaction is the reverse of formation. The enthalpy change is 3 * (Enthalpy of formation of NH3) / (moles in reaction). So, -46 kJ/mol * 2 = -92 kJ/mol.