IMFs Solutions 1046

IMFs Solutions Diethyl ether will have a higher vapor pressure because the –OH group on butanol is more polar than the C-O-C group, thus ether has weaker intermolecular attractions than butanol.   (a) HF – H=bonding, dipole-dipole, London forces (b) PCl3                                                                                                                                                                                                                                  The unshared pair on the P-atom makes the molecule polar thus: dipole-dipole, London forces. There are no H-atoms, so there is no H-bonding (c) SF6                                                                                                                                         SF6 is comprised of a perfectly symmetrical octahedron, thus it is non-polar. As a result, its only intermolecular forces are London forces.     (d) SO2   SO2 is polar, with a planar triangle geometry. Thus, we can expect dipole-dipole interactions as well as London forces   CHCl3 –B.P. = 61oC CHBr3 – B.P. = 149oC Both compounds are polar. Since Cl is much more electronegative than Br, CHCl3 is more polar and would be expected to form the strongest dipole-dipole attractions. But CHBr3 is heavier than CHCl3. Since CHBr3 characterized with the higher boiling temperature, its weight is more significant than its lesser intermolecular attractions.   CH3CH2OH – ethanol  - bp = 78.1oC CH3CH2SH – ethanethiol – bp = 35oC Ethanol would be expected to have the higher boiling point based on its stronger dipole-dipole forces between the –OH groups. Oxygen is much more polar than sulfur creating a stronger dipole-dipole interaction than the –SH group. Ethanol boils at twice the temperature of ethanethiol demonstrating the influence of the stronger dipole-dipole of ethanol over the higher molecular mass of ethanethiol.         5.  Water would be expected to have a higher heat of vaporization because it has a higher boiling point indicating it has stronger intermolecular attractions per molecular mass.