Question

Number of molecules in which lone pair or odd electron of central atom present in directional orbital

NH3, PH3, NO2, ClO3, H2O, CF3, CH3

Answer 1

7

Answer 2

All the given molecules (NH₃, PH₃, NO₂, ClO₃⁻, H₂O, CF₃, CH₃) have their central atom's lone pair or odd electron residing in a directional orbital.

• NH₃, PH₃, H₂O: Central atoms (N, P, O) are $sp^3$ hybridized, and lone pairs occupy $sp^3$ hybrid orbitals, which are directional.
• NO₂: Central atom (N) is $sp^2$ hybridized. The odd electron resides in an unhybridized $p$ orbital, which is directional.
• CF₃, CH₃: Central atoms (C) are $sp^3$ hybridized. The odd electron occupies an $sp^3$ hybrid orbital, which is directional.
• ClO₃⁻: Central atom (Cl) is $sp^3$ hybridized, and the lone pair occupies an $sp^3$ hybrid orbital, which is directional.

Therefore, all 7 molecules qualify.