Calculate the void volume of simple cubic unit cell if the volume of unit cell is $5.5 \times 10^{-22} \mathrm{~cm}^3$.

Calculate number of moles present in $9.10 \times 10^{-2} \mathrm{~kg}$ of water.

Identify the product 'B' in the following reaction.

Toluene $\xrightarrow[\mathrm{CS}_2]{\text { Chromylchloride }} \mathrm{A} \xrightarrow{\mathrm{H}_3 \mathrm{O}^{+}} \mathrm{B}$

Which from following properties of lanthanoids is NOT true?