WAEC - Chemistry (1989 - No. 25)
Given that for the reaction. N2(g) + 3H2(g) ⇌ 2NH3(g) ∆H = -92kJ. What is the enthalpy of formation of ammonia from its elements?
-46KJ mol -1
-184KJmol -1
-92KJmol -1
184KJmol -1
+46KJmol -1
คำอธิบาย
In the reaction the enthalpy of formation 2 mole of NH3 is - 92kJ. Therefore the standard \(\Delta H\) of formation = \(\frac{-92kJ}{2} = -46KJmol^{-1}\).