Free energy change G is measure of the spontaneity of a chemical reaction or process.
-n =number of moles of electron
F= the quantity of electrical charge that is contained in 1mole of electrons.This is the Faraday constant i.e. 1F= 96500 Coloum/mole of electron
F and n are positive value. therefore as positive value of E (which indicte spontaneity )and thus negtive value for G (which also indicate spontaneity)
= 1.05 V – 0.0295 x log 80
= 1.05 V – 0.0295 x 1.9031
= 1.05 V – 0.056 = 0.99 V.