According to VBT any covalent bond will be formed by overlapping of atomic orbitals of bonded atoms — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Step 1: Identify the nature of intermolecular forces in HF, NH3, and H2S. HF and NH3 exhibit strong intermolecular hydrogen bonding, whereas H2S only exhibits weaker van der Waals forces. Step 2: Compare the hydrogen bond strengths of HF and NH3. Since fluorine is more electronegative than nitrogen, HF forms much stronger hydrogen bonds than NH3, giving HF a higher boiling point. Step 3: This results in the boiling point order: HF > NH3 > H2S, corresponding to option (a).