Question

Which molecule or compound below contains a polar covalent bond?

C2H4

AgCl

KF

NI3

MgS

 

Answer 1

For covalent bond, both the elements between which bond is formed must be non metal.

AgCl is ionic and Ag is metal and Cl is non metal

KF is ionic and K is metal and F is non metal

MgS is ionic and Mg is metal and S is non metal

Only covalent compounds are C2H4 and NI3

The electronegativity difference between C and H is close to O

So, C-H bond is non polar.

The electronegativity difference between N and I is large

So, N-I bond is polar.

This is the reason NI3 is right answer