Which of the following set of species have planar structures? — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Step 1: The relationship between the bond angle θ and the hybridization parameter is related to the s-character by the formula: cos(θ) = s / (s - 1), where s is the decimal fraction of s-character. Step 2: For a bond angle of 120°: cos(120°) = -0.5. Substituting into the formula: -0.5 = s / (s - 1) => -0.5s + 0.5 = s => 1.5s = 0.5 => s = 1/3 ≈ 0.333. Step 3: A fractional s-character of 1/3 corresponds to exactly 33.3% s-character, which is typical of sp2 hybrid orbitals. Thus, option (b) is correct.