Which among the following is NOT a feature of $\mathrm{S}_{\mathrm{N}} 2$ mechanism?

3.4 moles of an ideal gas occupies volume of 68 mL at 300 K . What would be the pressure of gas? $\left(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$

Which of the following alloys is used in construction of outer fuselage of ultra-high speed air craft?

Calculate the percentage dissociation of 0.05 M solution of weak electrolyte if its molar conductivity and molar conductivity at infinite dilution are respectively. $3.3 \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ and $132 \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$.