ترجمه آماده – نیروهای بین مولکولی

Intermolecular forces- forces of attraction and repulsion between molecules that hold molecules, ions, and atoms together.

Boiling Point

– the temperature at which the liquid form of a compound vaporizes into a gas.

– the attractive forces in the liquid must be overcome to become a gas.

– boiling point of 0 = no attractive force

Explain trend in boiling points of H Halides: HCl, – 85`C; HBr, -67`C; HI, -15`C

Answer:

Stronger intermolecular forces result in higher boiling points. The dipole moments increase with the polarity of the H-X bond (the greater the difference in EN between the H and halogen atoms, the stronger the dipole-dipole attractions.) The strength of London forces increases with the number of electrons Cl is more EN than I so HCl should have a greater boiling point but this data suggests that London forces dominate dipole-dipole interactions for these molecules since Iodine is larger than Cl.