Find out the correct hybridisation of the central atom in $\mathrm{BCl}_3, \mathrm{PCl}_5, \mathrm{NH}_3$ and $\mathrm{SF}_6$.

• A

  $\left(\mathrm{BCl}_3: s p^3\right) ;\left(\mathrm{PCl}_5: s p^3 d^2\right) ;\left(\mathrm{NH}_3: s p^2\right)$ and $\left(\mathrm{SF}_6: s p^3 d\right)$
• Correct answer
  B

  $\left(\mathrm{BCl}_3: s p^2\right) ;\left(\mathrm{PCl}_5: s p^3 d\right) ;\left(\mathrm{NH}_3: s p^3\right)$ and $\left(\mathrm{SF}_6: s p^3 d^2\right)$
• C

  $\left(\mathrm{BCl}_3: s p^2\right) ;\left(\mathrm{PCl}_5: s p^3 d^2\right) ;\left(\mathrm{NH}_3: s p^3\right)$ and $\left(\mathrm{SF}_6: s p^3 d\right)$
• D

  $\left(\mathrm{BCl}_3: s p^3\right) ;\left(\mathrm{PCl}_5: s p^3 d\right) ;\left(\mathrm{NH}_3: s p^2\right)$ and $\left(\mathrm{SF}_6: s p^3 d^2\right)$

Solution

It is defined as the concept of mixing two atomic orbitals with the same energy levels to give a degenerated new type of orbitals. Hybridisation $=\frac{\text{Number valence electrons } \pm \text{ Charge }+ \text { Number of single bonded atoms }}{2}$

Hence, the correct answer is option: 'B'.