A, B, C and D are some compounds. The enthalpy of formation of A ( g ), B ( g ), C ( g ) and D ( g ) is 9.7,-110,81 and -393 ~kJ ~mol ⁻¹ respectively. What is r H ( . in . kJ mol ⁻¹ ) for the given reaction? A ( ~g )+3 ~B ( ~g ) C ( ~g )+3 D ( ~g )

Step-by-step solution

Given, aligned & H _ A ( ~g )=9.7 ~kJ ~mol ⁻¹ & H _ B ( ~g )=-110.81 ~kJ ~mol ⁻¹ & H _ C ( ~g )=81 ~kJ ~mol ⁻¹ & H _ D ( ~g )=-393 ~kJ ~mol ⁻¹ & ~A ( ~g )+3 ~B ( ~g ) C ( ~g )+3 D ( ~g ) & array l H H array = H _ product - H _ Reactant & =[3 (-393)+81]-[9.7+3(-110)] & =-1098+320.3 & _ r H =-777.7 ~kJ ~mol ⁻¹ aligned