Which among the following compounds has highest boiling point?

What is IUPAC name of the following compound?

What is molar mass of metal with BCC structure having density 10 g cm$$^{-3}$$ and edge length 200 pm?

Calculate difference between $$\Delta \mathrm{H}$$ and $$\Delta \mathrm{U}$$ for following reaction at $$25^{\circ} \mathrm{C}$$ ?

$$\mathrm{C}_2 \mathrm{H}_{6(\mathrm{~g})}+3.5 \mathrm{O}_2 \rightarrow 2 \mathrm{CO}_{2(\mathrm{~g})}+3 \mathrm{H}_2 \mathrm{O}_{(l)}\left(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$$