- Ni 3.23−(−0.44)=+0.21V ∆G∘=−nFE∘=(−2×0.21)F ∆G∘=−0.42F Platiimum -ve value of ∆G∘ is possible in -ve, ∆G∘=+ ve and ve, ∆G∘=− ve (a), (b) and (c) give positive ∆G∘ (d) and (e) give ∆G∘ negative. But for ∆G∘ is more -ve. Position of ammonium dichromate heating gives N2,Cr2O3 and H2O as