What is molar conductivity at zero concentration in $\Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ for aluminium sulphate, if molar ionic conductivities at zero concentration of $\mathrm{Al}^{+3}$ and $\mathrm{SO}_4^{-2}$ are $189 \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ and $50.1 \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ respectively?

Which of the following compounds is an optically inactive compound?

Which of the following reagents is used in the conversion of phenol into picric acid?

Which of the following is an example of second order reaction?