Which one of the following does not follow octate rule?

• A

  $\mathrm{PF}_{3}$
• Correct answer
  B

  $\mathrm{BF}_{3}$
• C

  $\mathrm{CO}_{2}$
• D

  $\mathrm{CCl}_{4}$

Solution

$\mathrm{BF}_{3}$ does not follow octate rule because central atom, boron lacks an electron pair. Thus, it also acts as Lewis acid.

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