EXERCISES

Suggest reasons why the $\mathrm{B}–\mathrm{F}$ bond lengths in ${\mathrm{BF}}_3 (130 \mathrm{pm})$ and ${{\mathrm{BF}}_4}^{–} (143 \mathrm{pm})$ differ.

If $\mathrm{B}–\mathrm{Cl}$ bond has a dipole moment, explain why ${\mathrm{BCl}}_3$ molecule has zero dipole moment.

Aluminium trifluoride is insoluble in anhydrous $\mathrm{HF}$ but dissolves on addition of $\mathrm{NaF}$. Aluminium trifluoride precipitates out of the resulting solution when gaseous ${\mathrm{BF}}_3$ is bubbled through. Give reasons.

Write balanced equations for: ${\mathrm{H}}_3{\mathrm{BO}}_3\stackrel{∆}{\to }$

Write balanced equations for: $\mathrm{Al} + \mathrm{NaOH} \to$

Write balanced equation for: ${\mathrm{B}}_2{\mathrm{H}}_6 + {\mathrm{NH}}_3 \to$

Elements of group $14$

If the starting material for the manufacture of silicones is ${\mathrm{RSiCl}}_3$, write the structure of the product formed.