Which one of the following arrangement of molecules is correct on the basis of their dipole moments?

Question

Which one of the following arrangement of molecules is correct on the basis of their dipole moments? (A) BF3>NH3>NF3 (B) BF3>NF3>NH3 (C) NH3>BF3>NF3 (D) NH3>NF3>BF3

Tardigrade Admin · Accepted Answer

Both NF3 and NH3 have identical shape (pyramidal) and a lone pair of electron on nitrogen. Dipole moment of NH3 is higher than NF3 molecule as the orbital moment due to lone pair of electrons and the resultant dipole moment of 3 N-F bonds point in the opposite directions to that of lone pair of electrons. BF3 is a symmetrical molecule. It has zero dipole moment. <img class="img-fluid question-image" alt="Solution" src="https://cdn.tardigrade.in/q/nta/c-zszpqoq8zbi4mrna.jpg" />

Q. Which one of the following arrangement of molecules is correct on the basis of their dipole moments?

$B F_{3} > N H_{3} > N F_{3}$

$B F_{3} > N F_{3} > N H_{3}$

$N H_{3} > B F_{3} > N F_{3}$

$N H_{3} > N F_{3} > B F_{3}$

Q. Which one of the following arrangement of molecules is correct on the basis of their dipole moments?

BF3​>NH3​>NF3​

BF3​>NF3​>NH3​

NH3​>BF3​>NF3​

NH3​>NF3​>BF3​

$B F_{3} > N H_{3} > N F_{3}$

$B F_{3} > N F_{3} > N H_{3}$

$N H_{3} > B F_{3} > N F_{3}$

$N H_{3} > N F_{3} > B F_{3}$