Given F ( g )+ e ⁻ F ⁻( g ) (Electron gain enthalpy) Li ⁺( g )+ F ⁻( g ) LiF ( s ) -1047 Li ( s )+ 1 2 ~F ₂( ~g ) LiF ( s ) -617 Based on data provided, the value of electron gain enthalpy of fluorine would be:

Step-by-step solution

Applying Hess's Law array c _ f H ^ = _ sub H + 1 2 _ diss H + L .E. + E . A + _ lattice H -617=161+520+77+ E A .+(-1047) E . A .=-617+289=-328 ~kJ ~mol ⁻¹ array electron affinity of fluorine =-328 ~kJ ~mol ⁻¹