The correct set of species with zero dipole moment is:
$(i) \, CO_2, \, (ii) \, COCl_2, \, (iii) \, CH_2Cl_2, \, (iv) \, BCl_3$

Match the following molecules in List-$I$ with their respective dipole moments in List-$II$:
| List-$I$ (Molecules) | List-$II$ (Dipole moment $\mu$,$D$) |
| :--- | :--- |
| $A. \ H_2O$ | $I. \ 0$ |
| $B. \ BF_3$ | $II. \ 0.23$ |
| $C. \ NH_3$ | $III. \ 1.47$ |
| $D. \ NF_3$ | $IV. \ 1.85$ |

Which out of $NH_3$ and $NF_3$ has higher dipole moment and why?

Consider the following:
Assertion $(A)$: Dipole moment of $NF_3$ is lesser than $NH_3$.
Reason $(R)$: In $NF_3$,the orbital dipole due to lone pair of electrons is in the opposite direction to the resultant dipole moment of the three $N-F$ bonds.
The correct answer is:

Which molecule has both non-polar and polar bonds,but the molecule as a whole is polar?

Identify the correct order of average molecular dipole moment for the following species: $PCl_3F_2$, $N_2O_{4(g)}$, and $N_2O_{4(s)}$.