Q12. Ammonium chloride dissociation thermodynamics
The dissociation vapour pressure of solid NH₄Cl is 608 kPa at 427° C and 1115 kPa at 459° C. Find (i) the equilibrium constant, (ii) standard reaction Gibbs energy, (iii) standard enthalpy and (iv) standard entropy at 427° C. Treat gases as perfect and ΔH°,ΔS° as constant over the interval.
Answer in brief
Using a 1-bar gas standard state: Kₚ=9.2416, ΔᵣG°=-12.94 kJ mol⁻¹, ΔᵣH°=161.53 kJ mol⁻¹ and ΔᵣS°=249.2 J mol⁻¹ K⁻¹.
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CoversAmmonium chloride dissociation thermodynamicsChemical equilibrium