For the reaction
`C_(2) H_(6) to C_2 H_4+H_2`
the reaction enthalpy `Delta_r H= " ____________ " kJ mol^(-1)`.( Round off to the Nearest Integer).
[Given : Bond enthalpies in kJ `mol^(-1) : C-C : 347, C=C:611,C-H:414, H-H:436` ]

Calculate DeltaH^(@) ("in" kJmol^(-1)) for the reaction CH_(2)Cl_(2)(g)rarrC(g)+2H(g)+2Cl(g). The average bond enthalpie of C-H and C-C1 bonds are 414 kJ mol^(-1) .

Calculate the resonance energy of C_(6)H_(6) using kekule formula of C_(6)H_(6) from the following data. a. Delta_(f)H^(Theta) for C_(6)H_(6) =- 358.5 kJ mol^(-1) b. Heat of atomisation of C =716.8 kJ mol^(-1) c. Bond enegry of C-H, C-C, C=C and H-H are 490, 620, 436.9 kJ "mole"^(-1) respectively.

Calculate the enthalpy of hydrogenation : C_(2)H_(5)(g) + H_(2)(g) to C_(2)H_(6)(g) Given that the bond enthalpies of H - H , C = C, C- C and C - H bonds are 433, 615, 347 and 413 kJ mol^(-1) respectively.