The substance that has the lowest boiling point is: — p Block Elements Chemistry Question

💡 Solution & Explanation

Step 1: The boiling points of molecular hydrides depend on the strength of their intermolecular forces. Step 2: HCl, H2S, and PH3 are polar molecules and exhibit dipole-dipole attractions in addition to London dispersion forces. Silane (SiH4) is highly symmetric and completely non-polar. Step 3: Consequently, SiH4 is held together solely by exceptionally weak dispersion forces, giving it the lowest boiling point in the series. Thus, option (d) is correct.