F2(g) + 2e− → 2F−(aq) E0 = +2.87 V
Cl2(g) + 2e− → 2Cl−(aq) E0 = +1.36 V
reduction potential for fluor is highest, which means it will be the reduced species, so indeed:
2 Cl- + F2 -> Cl2 + 2 F- (E0, cell = 2.87 - 1.36 = 1.21 V ) is the preferred reaction.