InterviewSolution
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InterviewSolution
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Calculate the value of log `K_(p)` for the reaction `N_(2)(g)+3H_(2)(g) hArr 2NH_(3)(g)` at `25^(@)C`. The standard enthalpy of formation of `NH_(3)(g)`is`-46kJ` and standard entropiesof `N_(2)(g), H_(2)(g)` and`NH_(3)(g)` are are 191,130,193`JK^(-1) mol^(-1)` respectively . `( R = 8.3 JK^(-1) mol^(-1))` |
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Answer» `Delta_(f)G^(@) (NH_(3)) = DeltaH^(@) - TDeltaS^(@) = -46000- ( 298 xx192) J mol^(-1) = - 103.2 kJ mol^(-1)` `Delta_(f)G^(@) (N_(2))= DeltaH^(@) - T DeltaS^(@) = 0 -298 xx191 J mol^(-1) = -56.9 kJ mol^(-1)` `Delta_(f)G^(@) ( H_(2)) = DeltaH^(@) - T DeltaS^(@) =0 - 298 xx 130 J mol^(-1) = - 38.74kJ mol^(-1)` `DeltaG^(@)` for reaction `Delta _(r)G^(@) = 2 xx Delta_(f)G^(@) ( NH_(3)) - Delta_(f)G^(@) ( N_(2))-3Delta_(f)(H_(2)) =- 206.4 +56.9 +116.2 = - 33.28 kJ mol^(-1)- DeltaG^(@) =2.303 RT log K` ` 33.28 = 2.303 xx (8.314 xx 10^(-3)) log K` or `log K =1.738 xx 10^(3)` |
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