Question

Which one of the following should have the lowest boiling point? HCl PH3 H2S C2H6 C3H7OH

Answer 1

H2S is expected to have the lowest boiling point among the given compounds.

Step-by-step explanation:

Among the given compounds (HCl, PH3, H2S, C2H6, C3H7OH), H2S is expected to have the lowest boiling point. This is because H2S has the smallest molar mass among the compounds, so it has weaker dispersion forces compared to the others. Dispersion forces increase with increasing molar mass, so the compound with the highest molar mass (C3H7OH) would have the highest boiling point.

Answer 2

`C_2H_6`

Step-by-step explanation:

The boiling point depends on the intermolecular forces between the molecules of the compound.

`HCl,\ H_2S\ and\ PH_3` have dipole- dipole interactions because there is the difference in electronegativity values of the atoms in the molecules.

`C_3H_7OH` posses hydrogen bonding.

`C_2H_6` : The bond in the molecule is C-H, which is non-polar in nature because the carbon and the hydrogen having very similar electronegativity values.

The intermolecular force acting in the molecule are induced the dipole-dipole forces or London Dispersion forces / van der Waals forces which are the weakest intermolecular force.

Hence, it has the weakest bond, so it takes least amount of the energy and hence the lowest boiling point.