intermolecular-forces (3rd q) Flashcards
What are intermolecular forces?
Attractive forces between molecules.
Intramolecular forces hold atoms together within a molecule.
What are intramolecular forces?
Forces that hold atoms together in a molecule.
How do intermolecular forces compare to intramolecular forces?
Intermolecular forces are generally much weaker than intramolecular forces.
What is the measure of intermolecular force related to vaporization and fusion?
ΔHvap (heat of vaporization), ΔHfus (heat of fusion), ΔHsub (heat of sublimation).
What is a hydrogen bond?
A special dipole-dipole interaction between the hydrogen atom in a polar N-H, O-H, or F-H bond and an electronegative O, N, or F atom.
Why is the hydrogen bond considered a special dipole-dipole interaction?
It involves specific electronegative atoms (N, O, F) and is stronger than regular dipole-dipole interactions.
What are ion-dipole forces?
Attractive forces between an ion and a polar molecule.
What are dipole-dipole forces?
Attractive forces between polar molecules.
What are dispersion forces?
Weak attractive forces that arise from temporary dipoles induced in atoms or molecules.
What factors increase polarizability?
Greater number of electrons and a more diffuse electron cloud.
What is surface tension?
The amount of energy required to stretch or increase the surface of a liquid by a unit area.
What is cohesion?
The intermolecular attraction between like molecules.
What is adhesion?
An attraction between unlike molecules.
What is viscosity?
A measure of a fluid’s resistance to flow.
What is vapor pressure?
The pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases at a given temperature in a closed system.
What is molar heat of vaporization (Hvap)?
The heat absorbed by one mole of a substance as it is converted from a liquid to gas.
Fill in the blank: Strong intermolecular forces result in _______ surface tension.
high
Fill in the blank: Strong intermolecular forces result in _______ viscosity.
high
True or False: Ice is less dense than water.
True
What is a phase?
A homogeneous part of the system in contact with other parts of the system but separated from them by a well-defined boundary.
What are the two phases of water?
Solid phase (ice) and liquid phase (water).
What type of intermolecular forces exist between HBr molecules?
Dipole-dipole forces and dispersion forces.
What type of intermolecular forces exist between CH4 molecules?
Dispersion forces.
What type of intermolecular forces exist between SO2 molecules?
Dipole-dipole forces and dispersion forces.
