Question

Which compound most likely contains polar covalent bonds? NaCl AlF3 Br2 NF3

Answer 1

Answer: The correct answer is $NF_3$

Explanation:

In $NF_3$ molecule, there are three bond pairs and one lone pair present in the molecule. In a molecule, lone pair present on the nitrogen atom will have a dipole moment in upward direction where as total dipole moment formed by three fluorine atoms will be more in magnitude and it will be directed in downward direction which means that the net dipole moment will be in downward direction. As shown in image attached.

Hence, covalent bond present between nitrogen and fluorine will become polar in nature.

So, the correct answer is $NF_3$.

Answer 2

Answer:

The correct option is $NF_3$

Step-by-step explanation:

we have to select the compound which most likely contains polar covalent bonds.

In polar covalent bond, the electrons shared by the atoms spend a greater amount of time, on the average. This is due to electronegativity difference between the two atoms in the molecule.

NaCl is purely ionic bond strong electrostatic forces of attraction between positively charged Na and negatively charged Cl.

$AlF_3$ is ionic.

$Br_2$ is a non-polar molecule both atoms are equally electronegative, neither of them withdraws electron density from the single covalent bond between them.

In molecule,$NF_3$ there are three bond pairs and one lone pair present in the molecule. In a molecule, lone pair present on the nitrogen atom will have a dipole moment in upward direction whereas total dipole moment formed by three atoms of fluorine will be more in magnitude and it will be directed in downward direction which means that the net dipole moment will be in downward direction. As shown in image attached.

Hence, covalent bond present between the atoms  nitrogen and fluorine will become polar in nature.

The correct option is $NF_3$