Conjugate acid of $\mathrm{NH}_2^{-}$and $\mathrm{NH}_3$ are respectively

Calculate the value of $\Delta G$ for the following reaction. $\mathrm{N}_2 \mathrm{O}_{4(\mathrm{~g})} \longrightarrow 2 \mathrm{NO}_{2(\mathrm{~g})}$ if $\Delta \mathrm{H}=57.44 \mathrm{~kJ}$ and $\Delta \mathrm{S}=176 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$.

Calculate the radius of first orbit of $\mathrm{Li}^{++}$.

Which from following polymers (trade name) is used to obtain paints?