Identify the structure of $\mathrm{XeF}_4$ molecule from following.

Calculate $\left[\mathrm{H}_3 \mathrm{O}^{+}\right]$in 0.02 M solution of monobasic acid if dissociation constant is $1.8 \times 10^{-5}$.

Which from following statements is NOT true according to principles of green chemistry?

The molar conductivity of 0.02 M KCl solution is $410 \Omega^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$ at $25^{\circ} \mathrm{C}$. Calculate its conductivity?