Calculate $$\Delta \mathrm{G}^{\circ}$$ for the cell:

$$\mathrm{Sn}_{(\mathrm{s})}\left|\mathrm{Sn}_{(\mathrm{1M})}^{2+}\right|\left|\mathrm{Ag}_{(\mathrm{1M})}^{+}\right| \mathrm{Ag}_{(\mathrm{s})}$$ at $$25^{\circ} \mathrm{C}\left(\mathrm{E}_{\text {cell }}^{\circ}=0.90 \mathrm{~V}\right)$$

Which from following statements is NOT correct?

A compound made of elements $$\mathrm{A}$$ and $$\mathrm{B}$$ form fcc structure. Atoms of A are at the corners and atoms of B are present at the centres of faces of cube. What is the formula of the compound?

What are different possible oxidation states exhibited by scandium?