chemistry chapter 13

the kelvin temperature of a substance is directly proportional to the average kinetic energy of the particles of the substancewhat is the relationships between the temperature in kelvins and the average kinetic energy of particlesthe interplay between the disruptive motions of particles in a liquid and the attraction among the particles determines the physical properties of liquidswhat factor determine the physical properties of a liquidduring evaporation, only those molecules with a certain minimum kinetic energy can escape from the surface of the liquidwhat is the relationship between evaporation and kinetic energyin a system at constant vapor pressure , a dynamic equilibrium exists between the vapor and the liquid. the system is in equilibrium because the rate of evaporation of liquid equals the rate of condensation of vaporwhen can a dynamic equilibrium exist between a liquid and its vaporvapor pressurea measure of the force exerted by a gas above the liquidwhen a liquid is heated to a temperature at which particles throughout the liquid have enough kinetic energy to vaporize , the liquid begins boilunder what conditions does boiling occurboiling pointis the temperature at which the vapor pressure of the liquid is just equal to the external pressure on the liquidnormal boiling pointis defined as the boiling point of a liquid at a pressure of 101.3 kPathe general properties of solids reflect the orderly arrangement of their particles and the fixed locations of their particleshow are the structures and properties of solids relatedmelting pointis the temperature at which solids changes into a liquidfreezing pointis the temperature at which a liquid changes into a solidthe shape of a crystal reflects the arrangement of the particles within the solidwhat determines the shape of a crystalunit cellthe smallest group of particles within a crystal that retains the geometric shape of the crystalallotropesare two or more different molecular forms of the same element in the same physical stateamorphous solidlacks an ordered internal structuresublimationthe change of a substance from a solid to a vapor without passing through the liquid statesublimation occurs in solids with vapor pressures that exceed atmospheric pressure at or near room temperaturewhen can sublimation occurthe conditions of pressure and temperature at which two phases exist in equilibrium are indicted on a phase diagram by a line separating the two regions representing the phaseshow are the conditions at which phases are in equilibrium represented on a phase diagramphase diagramgives the conditions of temperature and pressure at which a substance exists as solid, liquid , or gas (vapor)triple pointa point on the diagram where all three lines meet. describes the only set of conditions at which all three phases can exist in equilibrium with one anothermolecules or atomsthe particles in gas are usually ...travel in a straight line until they collide with another particle or object like a wallhow do the particles of gas travelthey can change direction when they rebound from collisions with one another or objectshow do particles of gas change directionrandom walkwhat is the aimless path the molecules take calledkinetic energy is transferred without loss from one particle to another, and the total kinetic energy remains constantduring an elastic collision what happens with kinetic energymoving bodies exert a force when they collide with other bodieswhat causes a force within gas pressuregravity holds the particles in air within earths atmospherehow does air exert pressure on earthit decreases because the density of earths atmosphere decreases as the elevation increaseswhat happens to atmospheric pressure as you climb up a mountain and whyweather and altitudewhat does atmospheric pressure depend onparticles absorb energy , some of which is stored within the particlesas substances are heated what happens with its particlespotential energystored energy in a particlesnodoes potential energy in a particle raise the temperature of the substancespeeds up particles which increases their kinetic energy which results in a temperature changewhat does the remaining absorbed energy dosame average kinetic energyat any given temperature, the particles of all substances , regardless of physical state, what do they all havesubstances temperaturethe average kinetic energy of the particles in a substance is directly related to whatabsolute zero or -273.15at which temperature does particles have zero kinetic energythe relationship between temperature and average kinetic energywhat does the kelvin temperature scale reflectkinetic energyaccording to kinetic theory , both the particles in gases and the particles in liquids have whatpass on anotherthe energy , kinetic energy , present in the particles in the gases and liquids allow gases and liquids to whatfluidssubstances that can flow are referred to asgasaccording to kinetic theory, there are no attractions between the particles in whatattracted to each otherthe particles in a liquid are whatthe particles are attracted to each otherwhy do liquids have a definite volumeparticlesintermolecular attractions reduce the amount of space between what in a liquidvolumeincreasing the pressure on liquid hardly has an effect on its what ? this is also true for solidssolid and liquidwhat to stages of matter are known as condensed states of matterwater vaporwater in an open container escapes into the air as whatkinetic energymost of the molecules in a liquid don't have enough what to overcome the attractive forces and escape into the gaseous statedecreasesas evaporation occurs, the liquids temperature whatcooling processevaporation is a whatpressurewhen a partially filled container of liquid is sealed, some of the particles at the surface of the liquid vaporize. these particles collide with the walls of the sealed container, producing whatliquidwhen some of the particles entering the vapor increase and some of the particles condense and return to which statevaporizingthe number of particles condensing will equal the number of particlesvapor pressure; the particles in the warmed liquids have increased kinetic energyan increase in temperature of a contained liquid increase what kind of pressure ? and why does this happendiethyl etherwhat kind of liquid is the most volatilewaterwhat kind of liquid is the least volatilemanometerthe vapor pressure of a liquid can be determined with a device calledrisesaverage kinetic energy of the particles in liquid increase and the temperature of the liquid whatexternal pressureliquids boil when its vapor pressure is equal to the whataltitudewhat affects the boiling point of waterhigher altitudesbecause atmospheric pressure is lower at higher altitudes, boiling points decrease at whatcoolingwhat kind of process is boiling ? cooling or heating?the liquid from which it escapedthe vapor produced by boiling is the same temperature as whatvapor ; thats why vapor burns or more severewhich has the higher potential energy, the boiling liquid or its vapor?its particles vibrate more rapidly as their kinetic energy increaseswhat happens when you heat a solidfixed positionsat melting point, the disruptive vibrations of particles are able to overcome the attractions which hold them in whattemperature ; therefore at that temperature solid and liquids are in equilibriumthe melting and freezing points of a substance are at the same whatmelting pointionic solids have a high what because relatively strong forces hold them togethersodium chloridewhats an example of an ionic compound with a high melting pointmolecular compoundswhat kind of solids have low melting pointsno, wood and sugar cane for example decompose when heateddo all solids melt?crystallinemost solid substances are whatthey are classified into their 7 groups or systemshow are crystals classifiedin terms of the angles between the faces and in the number of edges of equal length on each facehow do the seven crystal systems differthe arrangement of the particles within itthe shape of the crystal depend on whata repeating array of any one of fourteen kinds of unit cellswhat is a crystal latticecarbonwhat example of an element can exist in more than one formdiamond, graphite, fullerenesexamples of crystalline allotropes of carbonrubber, plastic, asphaltexamples of amorphous solidsolids, like liquids, have a vapor pressurewhy can sublimation occuriodinean example of a substance that can go under sublimation