Chapter 12 Chemistry Quiz

Intermolecular forces

Intermolecular forces

attractice forces that exsist between molecules

Surface tension

the tendency for liquids to minimize their surface area, increases with increasing intermolecular forces

Viscosity

the resistance of a liquid to flow, greater in subtances with stronger intermolecular forces because molecules can’t move around each other as freely

Why does evaporation occur below the boiling point?

molecules on the surface of the liquid experience fewer attractions to neighboring molecules

Dynamic equilibrium

rate of evaporation=rate of condensation

Why is steam burn more harmful that a liquid burn?

the steam condenses on your skin and this releases a large amount of additional heat (exothermic)

Heat of vaporization

amount of energy needed to vaporize one mole of a subtance at the boiling point

Heat of fusion

amount of energy needed to melt one mole of a substance at the melting point

Water

H2O

Melting point: 0.00

Heat of Fusion: 6.02kJ

Heat of Vaporization: 40.7kJ

London Dipersion Forces

momentary dipoles result from the movement of electrons

two non polar molecules interacting

presnet in all molecules and atoms

Dipole-Dipole forces

interactions between the permanant dioples of polar molecules

attractive forces between the positive end of one polar molecule and the negative end of another polar molecule

Hydrogen bonding

speical type of dipole where H is bonded with F,O, N

really sticky

Ion-Dipole Forces

force between an ion and a polar molecule