Boric acid in solid, whereas ${\mathrm{BF}}_3$ is gas at room temperature because of

• A

  Strong ionic bond in Boric acid
• B

  Strong van der Waal's interaction in Boric acid
• Correct answer
  C

  Strong hydrogen bond in Boric acid
• D

  Strong covalent bond in ${\mathrm{BF}}_3$

Solution

Inter-molecular structure of Boric acid(${\mathrm{H}}_3{\mathrm{BO}}_3$) in solid phase:

Boric acid has strong hydrogen bonding as we can see in the above figure, while ${\mathrm{BF}}_3$ does not. Therefore boric acid is solid.

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