Question

What happens to these physical properties as the strength of intermolecular forces increases?

My answers are there as well but its not correct

Increase or decrease?
a) melting point - increases
b) vapor pressure-increases
c) boiling point- increases
d) viscosity - decreases
e) surface tension - decreases

Answer 1

a) melting point - increases OK
b) vapor pressure-increases As the IM forces increase, it makes it harder for the molecules to escape to the vapor phase (the pressure of the gas over the liquid); therefore, the vapor pressure must decrease.
c) boiling point- increases OK
d) viscosity - decreases As IM forces increase it makes it harder for the molecules to slide across each other; therefore, the viscosity must increase.
e) surface tension - decreases As the IM forces increase, it makes the molecules attract more strongly; therefore, surface tension increases.