In the series HCl, HBr and HI, the boiling point increases in the order HCl < HBr < HI. This is due — p Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: Boiling point of molecular compounds (where hydrogen bonding is absent or negligible) is primarily determined by the strength of intermolecular van der Waals forces. Step 2: Van der Waals forces (specifically London dispersion forces) increase with increasing molecular size, mass, and polarizability. Down the halogen group from Cl to I, the size and number of electrons of the hydrogen halides increase significantly (HCl < HBr < HI). Step 3: Consequently, HI has the strongest van der Waals' forces of attraction, resulting in the highest boiling point in this series. Thus, option (c) is correct.