Types of IMF
Properties of Liquids
Solids
Solubility
Phase Changes
100
What are London dispersion forces?
Temporary attractive forces due to instantaneous dipoles in all atoms and molecules.
100
What is surface tension?
The energy required to increase a liquid's surface area due to cohesive forces.
100
What is a molecular solid?
Solid made of molecules held together by IMFs.
100
What does "like dissolves like" mean?
Polar solvents dissolve polar solutes; nonpolar dissolves nonpolar.
100
What is melting?
Solid → liquid.
200
What is dipole-dipole interaction?
Attractive force between the positive end of one polar molecule and the negative end of another.
200
What is viscosity?
A liquid’s resistance to flow, which increases with stronger IMFs.
200
What is an ionic solid?
Solid composed of positive and negative ions held by electrostatic forces.
200
What makes a substance polar?
Unequal sharing of electrons + asymmetrical shape.
200
What phase change is boiling?
Liquid → gas.
300
What is hydrogen bonding?
A strong dipole-dipole interaction involving H bonded to N, O, or F.
300
How does IMF affect boiling point?
Stronger IMFs result in a higher boiling point.
300
Give an example of a network covalent solid.
Diamond (carbon) or quartz (SiO₂).
300
Why does NaCl dissolve in water?
Ion-dipole attraction between Na⁺/Cl⁻ and polar water molecules.
300
What is vapor pressure?
Pressure exerted by a vapor in equilibrium with its liquid.
400
Which IMF exists in all molecules?
London dispersion forces.
400
Define capillary action.
The movement of liquid within a narrow tube due to cohesive and adhesive forces.
400
Compare metallic and ionic solids.
Metallic: sea of electrons; Ionic: electrostatic attraction between ions.
400
Explain how IMF affects solubility.
Stronger IMF between solute and solvent = better solubility.
400
How do IMFs affect vapor pressure?
Stronger IMF = lower vapor pressure.
500
Rank LDF, D-D, and H-bond by strength.
H-bond > Dipole-dipole > LDF.
500
Explain why water has a high boiling point.
Because of strong hydrogen
500
Describe the properties of network covalent solids.
Very hard, high melting point, poor conductors (usually).
500
Predict solubility: hexane in water.
Insoluble – hexane is nonpolar, water is polar.
500
Describe the process of sublimation.
Solid → gas without becoming a liquid.