unit 3 properties of substances and mixtures

intermolecular forces

columbic forces, weaker than covalent bonds, creating positive and negative

dipole dipole interactions

polar + polar molecules, increased polarity, create a larger dipole moment

dipole induced dipole

polar + non polar molecules, shift electron density to create both positive and negative, induce dipole by pushing electrons and is temporary

London dispersion forces

non polar + non polar molecules, present in all IMF, lower temp enough to slow energy and form bond connection and turn into liquid, need a lot of IMF, temporary, larger the cloud the more polarizable and the stronger the interaction, need large molecule and enough IMF to hold non polar molecule together to form a liquid

hydrogen bonding

hydrogen + FON, very strong interaction

ion dipole

charged ion + polar molecule with dipole moment, dissolves

properties explained by IMF

when IMF are high: melting/boiling point (up), vapor pressure (down), volatility (down), surface tension (up), viscosity (up), heat of vaporization (up)

strength of IMF if size is similar

hydrogen bonding > dipole dipole > London dispersion forces

larger molecules

impact of LDF grows

4 types of solids

ionic, molecular, covalent network, metallic

brittle

if when subjected to stress it fractures with little elastic deformation and little plastic deformation

electricity

flow of electrons and charge

ionic solids

cations and anions arranged in repeating pattern, high boiling and melting, very brittle, cannot conduct electricity unless disolved in H2O, intra and inter strong

lattice distorted

everything shifts and breaks

molecular solids

neutral molecules form molecular lattice structures, boiling and melting low, cannot conduct electricity (uncharged), intra strong, inter weak

covalent network solids

distinct atoms bonded together covalently in 3D network, presence of metalloid (B, Si, Ge) or Diamond and Graphite, high melting, cannot conduct electricity

metallic solids

sea of electrons, variable melting, malleable and ductile, great conductor

solids

crystalline or amorphous, motion limited, molecules tightly packed

liquids

particles in close contact, molecules spread out

gas

constant motion, frequencies and spacing change

pressure

number and force of collisions with container

temperature

average kinetic energy energy of molecule, increased pressure

volume

amount of space in container

kinetic energy

½ (mass)(velocity)²

effect of volume on pressure

volume up, pressure down (larger space, less collisions)

effect of number of particles on pressure

less particles, less pressure, less collision

effect of temperature on pressure

higher temperature, higher pressure, molecules faster, more collisions

ideal gas law

PV=nRT

principles of ideal gas law

particles in constant, random motion; volume of 1 particle is zero compared to total volume; no attractive forces; collisions conserve kinetic energy; average kinetic energy is directly proportional to absolute temp

what temperature does molecular motion cease at

0 degrees kelvin

same temperature different mass

heavier molecules slower, narrower distributed; lighter molecules faster, wider distribution

same gas different temperature

higher temperature=higher velocity, wider distribution, lower temperature=lower velocity, narrower velocity

kinetic molecular theory

what makes ideal gas law work

how does pressure and size compare between real and ideal

attractive forces cause pressure down, and reduced collisions with wall, larger size has larger pressure

comparisons between ideal and non ideal

temp: higher and lower, pressure: lower and higher, IMF: insignificant, significant, size: smaller and larger