Answer:
[tex]C_2H_6[/tex]
Explanation:
The boiling point depends on the intermolecular forces between the molecules of the compound.
[tex]HCl,\ H_2S\ and\ PH_3[/tex] have dipole- dipole interactions because there is the difference in electronegativity values of the atoms in the molecules.
[tex]C_3H_7OH[/tex] posses hydrogen bonding.
[tex]C_2H_6[/tex] : 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.
