For the Reaction Fe^+3 + 3e^- = Fe, E° is -0.036V and E° for Fe^+3 +e^- = Fe^+2 is 0.771V.

Calculate E° for Fe^+2 +2e^- = Fe.

In solution according to Book,

Let Fe^+2 +2e^- = Fe -----------(1)

Firstly, find ∆G for each equation with given E° and then combine equation (and ∆G also) . After combining equation, we get required equation and ∆G for the required equation and then use simply for ∆G = -nFE

And we get required E°.

Here my problem is -

1. How do I get equation (1) after combining those equation (Like mathematics)

How does ot work.

2. How we get ∆G for equation (1) after combining those equation's ∆G.

**Is there any alternate ways for solving this question**