Given the following data:
l r
Reaction & Energy change (kJ)
Li(s)→ Li(g) & 161
Li(g)→ Li⁺(g) & 520
(1)/(2)F₂(g)→ F(g) & 77
F(g)+e⁻→ F⁻(g) & x
Li⁺(g)+F⁻(g)→ LiF(s) & -1047
Li(s)+(1)/(2)F₂(g)→ LiF(s) & -617
Based on the data provided, the value of electron gain enthalpy of fluorine would be: