Question

$BF_3$ and $NF_3$ both molecules are covalent, but $BF_3$ is non polar and $NF_3$ is polar. Its reason is

• A. In uncombined state boron is metal and nitrogen is gas
• B. $B - F$ bond has no dipole moment whereas $N - F$ bond has dipole moment
• C. The size of boron atom is smaller than nitrogen
• D. $BF_3$ is planar whereas $NF_3$ is pyramidal

Answer 1

Answer: (D)

$BF_3$ is planar while $NF_3$ is pyramidal due to the presence of lone pair of electron on nitrogen in $NF_3$.