Fluorine cannot be prepared from fluorides by chemical oxidation.
Fluorine is the strongest oxidizing agent as it has highest E0 value. Therefore fluorine has the highest tendency to get reduced to F-. As a result, F- ion has the least tendency to get oxidized, hence fluorine cannot be prepared by chemical oxidation of fluorides.
= 1.05 V – 0.0295 x log 80
= 1.05 V – 0.0295 x 1.9031
= 1.05 V – 0.056 = 0.99 V.