+ Br ( ) → 11th Std Chemistry 11th Std Chemistry - - - - MgBr (S) D H f = – KJ mol – Sublimation : Mg(S) → Mg(g) D H = + KJ mol – Ionisation : Mg(g) → Mg + (g) + 2e – D H = KJ mol – Vapourisation : Br ( ) → Br (g) D H = + KJ mol – Dissociation : Br (g) → 2Br(g) D H = + KJ mol – Electron affinity : Br(g) + e – → Br – (g) D H = – . KJ mol – Solution : Mg MgBr s H f (s) Br (l) ( ) → ∆ D H D H D H Br (g) u Br g Br g H ( ) ( ) ∆ → Mg g Mg g H ( ) ( ) ∆ → D H f = D H + D H + D H + D H + D H + u – = + + + + ( × – . ) + u – = + u u = – – u = – kJ mol – . Solution: Given T h = C = + = K T C = C = + = K % efficiency η = ?
h C h % . Solution: Given: S (urea) = . J mol – K – S (H O) = J mol – K – S (CO ) = . J mol – K – S (NH ) = .
J mol – K – NH – CO – NH + H O → 2NH + CO D