G.Chem 2

krabi's version from 2015-09-11 04:12

Section Thermodynamics

Question Answer
Define Depositiongas ⇒ solid, his hot air turned to shit during the deposition
Sublimation?Solid ⇒ gas; oppo. of deposition
Formula for Heats of Phase Change?q=nAH (q amount of heat = number of moles x heat of transition)
If Q is positive?Heat is put in
If Q is negativeYou have lost heat
Define Heat of Transition?Each substance has a specific AH; its magnitude is relation to strength and # of IMFs
Define CalorimetryWhat happens during phase changes? Matter absorbs/releases energy w/out undergoing transition.
IF a substance absorbs/releases heatTHEN temperature changes OR undergoes phase change
What is the relationship of q & AH?Direct correlation

Section Thermodynamics

Question Answer
What happens as heat is absorbed? KE goes UP and Entropy is up
What happens as heat is released? KE goes down and Entropy is down
Formula for intrinsic property?q=mcAT (sample mass x specific heat of temp. x temp.)
Define intrinsic propertytells us how resistant something is to changing temperature e.g. water is 1 calorie/gramC
What is the relationship between Temperature change & Heat Capacity of a substance?inverse relationship
Formula for Heat of Fusionq=nAH

Section Gases I

Question Answer
Define Heat of Fusionweakens bonds solid ⇒ gas
Define Heat of VapourizationBreaks bonds Liquid ⇒ gas
Define Triple PointWhere all three phases COexist in equilibrium
Define Critical PointEnd of critical liquid-gas boundary, with enuf temp and pressure ⇒ substance is squeezed into liquid phase
Critical Pt displays 2 properties?1) liquid@high density 2) gas@low viscosity
Super critical fluidLiquid and gas no longer distinct! No amount of pressure can force back into liquid phase.
How is water different?Liquid is denser than solid ice! Ice floats - solid-liquid boundary has -ve slope. eg. pressure of skate blade melts ice.
What is gas KMTgas has no fixed volume (unlike liquid/solid) more compressible and can move over long distances.
Gas molecules in ideal gas are …. (3 components of KMT)1) Average space is small w/ no volume 2) in constant motion random direction among collisions 3) Average KE proportional to Kelvin temperature
What is the Kelvin temp?C + 273.15
What is 1 atm pressure760 torr = 760 mm Hg

Section Gases Part II

Question Answer
Define ideal gas lawapplies to most real gases
Formula for ideal gas lawPV = nRT (0.0821)
Define Charles LawVolume = Temp.
Heat of phase changesq=mAH
IF freezing the ice creamTHEN releasing heat (q)
IF melting chocolateTHEN absorbs the heat
IF ice and liquid water co-exist at equilibriumTHEN temperature must be OC at 1 atm
IF changes in pressure and tempTHEN can induce phase change
Define Heat CapacityA proportionality constant that that defines how much heat is required to chance temp 1 C
What is the heat association w/phase changegiven by q=nAH
Why is more energy required to boil waterbecause water has H. bonding


Question Answer
IF pressure = constantTHEN gas will expand (heated) or will contract (cooled)
What law ties together pressure and KEV=T
IF temp is constantTHEN P ~ 1/V
What is the relationship between Pressure and Volume?Inverse relationship
In Boyle’s Law, IF volume goes downTHEN molecules have less space and pressure goes UP
IF volume is ConstantTHEN P ~ T
IF pressure goes UP THEN tempmust go UP because the molecules are moving faster and hitting the containter
IF n = constant THEN combined gas law isP1V1/T1 = P2V2/T2
IF there is branching THEN van der waals areinhibited