ap chem unit 3

UV or visible light

causes electrons to transition to different energy levels

infrared radiation

causes molecules to vibrate

microwave ratiation

causes molecules to rotate

c=λν

speed of light = wavelength*frequency

E=hν

energy of a single photon = Planck’s constant*frequency

Beer-Lambert Law

A = εbc (Absorbance = molar absorptivity * path length * concentration of the solution

outlier that’s too high on a concentration v. absorbance graph

contamination from a solution of higher concentration

outlier that’s too low on a concentration v. absorbance graph

contamination from water or a solution of lower concentration

more electrons = more polarizable =

stronger LDF

hydrogen bonds

molecules with O-H, N-H, or F-H bonds only

stronger attraction =

higher boiling and melting point

ionic solids

high melting point, brittle, conduct electricity when dissolved in water

covalent network solids

highest melting point, extremely high hardness, strongest covalent forces

molecular solids

low melting point, weak intermolecular forces

metallic solids

sea of electrons, excellent conductivity, malleable and ductile

true solids

crystalline structure, vibrational motion

amorphous solids

noncrystalline, vibrational motion

temperature

average kinetic energy of molecules in a sample

ideal gas

no intermolecular attractions, molecules don’t take up space

gases close to ideal gases

very small molecules, He, H2, Ne; high temperature and low pressure

distillation

different components of a mixture boil at different temperatures

vapor pressure