When the substances Si, KCl, CH3OH and C2H6 are arranged in order of increasing melting point, what — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Step 1: Categorize the solids formed by each substance: Si forms a giant 3D covalent network; KCl is an ionic lattice; CH3OH is a polar molecular solid with hydrogen bonding; C2H6 is a non-polar molecular solid with dispersion forces. Step 2: Covalent network solids (Si) have the highest melting points, followed by ionic solids (KCl). Among the molecular solids, the hydrogen-bonded CH3OH has a higher melting point than the non-polar C2H6. Step 3: This results in the correct increasing melting point order: C2H6 < CH3OH < KCl < Si.