Calculate number of atoms per unit cell of an element having molar mass $92.0 \mathrm{~g} \mathrm{~mol}^{-1}$ and density $8.6 \mathrm{~g} \mathrm{~cm}^{-3}$ forming cubic unit cell structure. $\left[\mathrm{a}^3 \times \mathrm{N}_{\mathrm{A}}=21.5 \mathrm{~cm}^3 \mathrm{~mol}^{-1}\right]$

What is the product obtained when phenylethene is treated with $\mathrm{KMnO}_4$ in dilute $\mathrm{H}_2 \mathrm{SO}_4$ ?

What is the pH of $10^{-8} \mathrm{M~HCl}$ solution?

What is the oxidation state of iodine in $\mathrm{I}_2 \mathrm{Cl}_6$ ?