The number of species from the following in which the central atom uses sp3 hybrid orbitals in its bonding is . NH3, SO2, SiO2, BeCl2, CO2, H2O, CH4, BF3
Answer
4
Solution
Steric number (SN) = σ bonds + lone pairs on the central atom; SN = 4 ⇒ sp3
NH3: 3 + 1 = 4 ⇒ sp3 ✓
SO2: 2 + 1 = 3 ⇒ sp2
SiO2: 3D network, each Si bonded to 4 O (SiO4 tetrahedra) ⇒ sp3 ✓
BeCl2: 2 + 0 = 2 ⇒ sp
CO2: 2 + 0 = 2 ⇒ sp
H2O: 2 + 2 = 4 ⇒ sp3 ✓
CH4: 4 + 0 = 4 ⇒ sp3 ✓
BF3: 3 + 0 = 3 ⇒ sp2
∴ sp3: NH3, SiO2, H2O, CH4 = 4
Answer: 4
Note: The official NTA answer key gives 3. Our faculty team has re-checked this question and finds 4 correct, as explained above.