Unit 8-Gas Laws

solids

molecules are strongly held together, strongest IMF’s

liquids

molecules are fairly held together, middle IMF’s

gases

molecules are weakly held together, weakest IMF’s

phase change

when IMF’s break, temperature does NOT change, energy is used to change states of matter

phase diagram

graph of the relationship between all three physical phases

triple point

temperature and pressure at which all three phases of that substance are at equilibrium

critical point

temperature and pressure at which gas and liquid phases coexist at equilibrium

supercritical fluid

phase where liquid and vapor pressures are indistinguishable, temperatures are above critical point

expansion, indefinite shape, compressibility, mixing, low denisty

characteristics of gases (5)

pressure

force caused by particles hitting the walls of a container

atmospheric pressure

force exerted on a surface by the air above which has weight as gravity pulls it down

boyles law

as pressure increases volume decreases, never boils

charles law

as volume increases temperature increases

gay-lussacs law

as pressure increases, temperature increases when volume is constant.

kinetic energy depends on temperature, no attractive or repulsive forces between particles, particles are in random motion, particles undergo collisions with no loss of kinetic energy

properties of ideal gases (4)

real gases

deviate from an ideal gas at low temperatures and high pressures, most gases like ideal gases at STP

avogadro’s law

as the number of particles increases so does the volume of the gas