AP Chem-Unit 3 (1-4)

The forces holding solids and liquids together

• much weaker than bonds -when substance melts/boils -- are broken

Interaction between ion and dipole Strongest of all intermolecular forces

Exist between neutral polar molecules Weaker than ion dipole If two molecules have about the same mass and size, the dipole-dipole forces increase with increasing polarity

Weakest of all the forces, exist between all molecules One molecule's electron cloud can become distorted causing an instantaneous dipole and that can induce another instantaneous dipole in an adjacent molecule/atom Forces between instantaneous dipoles are --- The strength of the LDF depends on how polarizable an atom or molecule is, more polarizable ->stronger LDF

1. Greater size (more electrons)

2. Shape (more electrons exposed, flatter)

3. The existence of pi bonds

Special case of Dipole Dipole forces H-F, H-O, H-N boiling points are extremely high --> intermolecular forces are high Requires: H bonded to a small, highly EN element (F,O,&N) an unshared electron pair on a nearby small, highly EN ion or atom

• -- Bond

• High MP

• Brittle and Hard

• Relatively Dense

• Dull Surface

• Conducts elec when melted or dissolved

• Ions

• Van der Waals forces

• Low MP

• Soft

• Low Density

• Dull Surface

• Cannot conduct electricity -Atoms or molecules

• --- Bond

• High MP

• Very Brittle and Hard

• Low Density

• Dull Surface

• Cannot conduct electricity Atoms in networks

• Atoms

• MP depends on e- configuration

• Ductile and Malleable and Very Hard

• Usually High Density

• Lustrous (Shiny)

• Can conduct electricity

No pattern to the arrangement of particles. Their melting point is over a wide range of temperatures. They just get softer and softer when heated. (Examples- glass, plastic, wax)

Well-ordered, definite arrangement of atoms.Crystals have a repeated structure and a melting point at a very narrow range of temperatures. (Examples- metals, H2O, diamond)

melting, evaporating/boiling & sublimation

freezing, condensation, & deposition

min temp required for a substance to become supercritical fluid

minimum pressure required to become super critical fluid

All 3 phases of matter at equilibrium

the heat energy required to evaporate a given mass of liquid at a constant temp

the heat energy required to melt a given mass of a solid at a constant temperature

resistance of a liquid

• thicker the liquid the more viscosity

• the stronger the IMF, higher ---

• as temp increases --- decreases

Acts as thin skin Bulk molecules (those in liquid) are equally attracted to their neighbors. Surface molecules are only attracted inwards towards the bulk molecules. Surface molecules are packed more closely. --- is the amount of energy required to increase surface area of a liquid

• Stronger IMF, greater ---

the point when as many molecules escape the surface as strike the surface.

is the pressure exerted when the liquid and vapor are in dynamic equilibrium.

the external pressure equals the vapor pressure.

is the boiling point at 760 mmHg (1 atm).

A substance with a high vapor pressure is said to be ---. It readily evaporates.

force acting on an object per unit area P= F/A

The pressures of gases not open to the atmosphere are measured in ---.

A --- consists of a bulb of gas attached to a U-tube containing Hg.

equal volumes of gas at the same temperature and pressure will contain the same number of molecules.

the volume of gas at a given temperature and pressure is directly proportional to the number of moles of gas.

Doubling the moles of gas in a balloon would double the volume of a balloon.

0 C or 273.15 K 1 atm or 760 mmHg or 101.3 kPa

nM/V or PM/RT (no more varun or please manage roy's things)

dRT/P (dirt pump)

X(specific mol/total mols)*P(total)