States of Matter: Liquids & Gases

when a gas is cooled

molecules lose their kinetic energy and allow van der Waal's attraction to take over and liquefy

pressure may be applied to a gas to a liquefy it under the ...

... critical temperature

why can't pressure above the critical temperature liquefy a gas?

too much kinetic energy

vapor pressure

a measure of the force exerted by a gas above a liquid

vapor pressure (increases/decreases) with higher temperatures

increases

volatile substance

substance that readily evaporates at room temperature because of high vapor pressure

inert substance

a substance that has almost no chemical reactivity except under extreme conditions

excipient

an inert substance added to a drug to form a suitable consistency for dosing

boiling point

the temperature at which the vapor pressure equals the atmospheric pressure

atmospheric pressure (increases/decreases) as you get closer to sea level

increases

boiling point (increases/decreases) with higher atmospheric pressure

increases

surface tension

the force that acts on the surface of a liquid and that tends to minimize the area of the surface

surfactants

compounds that lower the surface tension of water

surface tension (increases/decreases) with increasing temperature

decreases (intermolecular forces weaken)

viscosity

a fluid's internal resistance to flow

pressure

force applied over an area

units of pressure

pascals, atmospheres, mm Hg, psi

Boyle's law

volume and pressure of a gas are inversely related to

each other

V ∝ 1/P

Charles's law

volume (V) of a gas is directly proportional to ambient

temperature in degrees Kelvin

V ∝ T

Avogadro's law

volume of a gas is proportional to # of moles

V ∝ n

ideal gas law

PV = nRT

Dalton's law

the total pressure exerted by a mixture of gases is equal to the sum of partial pressures of the component gases

Henry's law

the dissolved gas in a liquid is directly proportional to the partial pressure of the gas above the liquid

decompression sickenss

injuries caused by a rapid decrease in the pressure that surrounds you