- GasLaws
Chemistry
Name
Period
Date
GasLawsComputer
Activity#1
Pressure
andTemperature
Gotoh
ies. Clickon "RunNow.,,
ln thisactivity,
youwillbe lookingat the relationship
betweenpressure
andtemperature
of a gas.
First,youneedto adda gasto yourcontainer.Changethe "Gas
in Chamber,,to read 100moleculesof
Heavy (blue) species,
Describethe motionof the particles:
Grabthe handleof the pumpandadd anotherpump-full.Besides
the obviouschangein theamountof
gas, what else changesin your container?
Click the "Reset,,button in the lower right.
ln this activity,we wantto examinethe rerationship
betweenpRESS)JRE andTEMPERATURE
onty. you
mustsetyourcontainer
to constant
volume.Clickon theVolumebufionin the "Constant
Parameters',
on the
upperrightcorner.Thisshouldlockyourvolumeat a constant
value.
As soonas you serectconstantvorume,whathappensto the box?
change the gas to 20o molecules of the HEAW speciesby manuaily
setting this in theright box.
You aregoingto adjustthe temperatureof
the container
by addingor removingheatusingtheHeatcontrot
underthecontainer.The temperature
of the internalenvii6nment
is foundaboie the container.
In whatunitsis temperature
reported?
Usingthe internet,
determine
the relationship
betweenKelvinand celsius.
Temperature
is a rerative
measureof energy.what temperature
is yourboxat?
Increasethe temperatureby using the "Heat control,,underyour container.
motion of the particlesin yourcontainer?
How does this affectfhe
Decreasethe temperature.what happensto the motionof the particres?
Returnthe temperatureto 300K.
The pressure
gaugeis foundon rightsideof the container.Whatunitsis
the pressuremeasured
in?
Again,increasethe temperatureto 600 K.
what happensto thenumber of collisions betweenthe molecules
andthe containerwall?
ln the end,howdoesthischangeaffectthe pressure
of the container?
what is the newpressure?
Fillin DataTable#1 by selecting
varioustemperatures
pressureon the
and recording
the corresponding
pressuregauge. choose a wide range of temperatures.But don't go too hot!
lnclude units. calculate the valuesas indicatedin the other columns.
DATATABLE#1
Trials
Trial1
(T)
Temperature
Pressure(P)
Calculatek1 = (Pxl)
Calculate
k, =F
300 K
2
3
4
5
6
Whichvariabledidyou manipulate
(independent)?
Whichvariableis the dependent
variable?
vs. Temperature
GraphPressure
graph. Useproperscaling.Labelthe graphappropriately.
in thefollowing
Graphthe lineof bestfit.
Lookingat yourdataandgraph,describe
the relationship
betweentemperature
and pressure.
gets colderand approaches
As thetemperature
0 K, what happensto the motionof the particles?
, )
Fillin the followingchart by selectingvariousVolumes.Measurethe volumeof the containerusingthe ruler.
Calculate
the valuesas indicatedin the other columns.
Trials
Volume(V)
Pressure
(P)
Cafculatek1=pxlf
Trial1
P
Calculate
k2= v
2
3
4
5
6
Whichvariabledid you control(independent)?
Whichvariableis the dependehtvariable?
GraphPressure
vs.Volumein the following
graph.Useproperscaling.Labelthegraphappropriately.
Drawa
curvedlinebestconnecting
allof the points.
Looking
at yourdataandgraph,describe
the relationship
between
volumeandpressure.
Asthe volumegetslarger,whathappens
to the pressure
of thegas?
e
Whichvalueremains
consistent
in the datatable?
k1 _ or
kz
Thisk-valueisconstant;
the ratiobetweenvolumeandtemperature
of anypointon the graphwill bethe
same.Pickanytwo pointsfromthe graphor table:
Point#L
point#2
V r=
Vz=
Pr=
Pt=
Showthe k-valuecalculation:
Write an equationfor Boyles'sLaw:
We canusethisformulato predictthe pressure
(P2)or volume(V2)of anygas.Usethisformulato complete
the followingcalculations.
your
Show
work.
L . l f a g a s h a s a v o l u m eLo. 2
f 5 L a n d a p r e s soufrLe. T l a t m , w h a t w i l l t h e p r e s s u r e b e i f t h e v o l u m e i s
changed
to 3.15L?
2. lf a gashasa volume of 3.67L and a pressureof 790 mm Hg,what will the pressurebe if the volumeis
compressedto2.LZ L? What is the pressurein atmospheres(atm)?Convertpressure
units.
3. A containerhasa volumeof 5.85 L and a pressureof 4.25 atm. What will the volumebe if the
container'spressureis changedto 2.75atm?
4. A containerhasa volumeof 2.79 L and a pressureof 5.97atm. lf the pressurechangesto 1460mm Hg,
what is the container'snew volume? Convertpressureunits.
As the temperaturegets approaches0 K, what happens
to the pressureof the container?
Increasethetemperature
to 2000K, whathappensto yourcontainer?
Whichvalueremainsconsistent
in the datatable?
kr
or
kz
Note: the other k-value is worthless and proves nothing.
Lookingat the top of DataTabre#1,whatdoesthis,,k,,value
equar?
Let'scallthe firstset of datapointsP1and11andthe second
set of datapointsp2and12and so on. sinceall
trialshaveroughlythe samechosenk-value,setthe r<-uuru"r
to equaleachother.write an appropriate
equationusingthe variables
pr, Tr, pz,dtldTz.
This is Gay'Lussac'sLaw betweenPressureand remperature
of a Gas. Learnit. Know it. use it.
we can usethisformulato predictthe pressule(Pr)or
temperature
ffr) of any gas. Usethisformulato
completethefollowingcalculations.
when doingtn'esecatiutations,'it
is n"."lr"ry for the pressure
to have
the sameunits. ldentifyall variables
andthen.in.titut"
solve.
"no
1' lf a gashasa pressureof 1.69atmat a temperature
of 300K, whatwillthe pressurechangeto if the
containeris cooledto 100K?
2' lf a gashasa pressureo'f715mm Hg
temperature
of 500 K, whatwillthe pressurechangeto if
the containeris heatedto 900 K? wrrat3ltn."
is ilris frJssuie in atmz
3' on the sideof aerosolcans,thereis warningagainstheating
the container.lf
gas insidethe
container
is at a pressureof 5.9 atm at roonite-mperature c),wnat wiit the
pressure
the
of thecanbe if
.eb"
the can is heatedto 100' c? Rememberto coniert io-Ketvin.
4. lf a containerof gas hasa temperature
of 2g0 K and a pressure
of 1.85atm,to whattemperature
would
you haveto heatthe containerto achieu"u pr"..uru
of 4.75 atm?
€
- GasLaws
Chemistry
Name
Period
Date
GasLawsComputer
Activity#2
V o l um eandTem per atur e
Goto http://phet.colorado.edu/en/simu
lation/eas-properties
. Clickon "Run Now."
ln this activity,you will be lookingat the relationship
betweenVOLIJMEandTEMPERATIJRE
of a gas.
First,youneedto add a gasto yourcontainer.Changethe "Gas in Chamber'n
to read 100moleculesof
Heavy(blue)species. Let the box equilibrate.
Whatis the pressureof yourcontainer?
ln this activityyou are examiningthe relationship
between VOLTJMEandTEMPERATIJRE
only. you must
set yourcontainerlo constantpressure.Clickon the Pressurebuttonin the "ConstantParameters"
in the
upperrightcorner.This shouldlockyourpressureat a constant
value(itmightfluctuatea verysmallamount).
As soonas you setthe pressure
to constant,
whathappensto the littlemannextto the box?
This littlerobotis responsible
for changing
the volumeof the container.Hispositionwillfluctuate.Whenyou
are trying to measure the volume of the container, you must estimatethe best averaqe position aid
record this value,
Thissimulation
doesnot havea toolto measurethevolumeof the container,
so we needto deviseone.
Glick on the ooMeasurement
Tools" buttonon the right side. Glickon the Ruler.
Thiswillcausea rulerto appear.Therulersunitsare in nanometers
(nm)butwe aregoingto usethe rulerto
giveus an estimated
measurement
of volume.Click on and drag the ruler anywhereyou want. Youwill
usetherulerto measurethewidthof the box. We willthenchangethe unitsof measurement
to liters.For
example:initially
the boxshouldhavea widthof 6.6 nm whichwillbe recorded
in yourdatatableas 6.6 L
(liters),Whenyouare askedto change/measure
the volumeof the box,usethe rulerto do so.
Whatarethe graduations
on the ruler?(Howmuchis eachnotchworth?)
You aregoingto adjustthetemperature
of the containerby addingor removingheatusingtheHeatControl
underthecontainer.The temperature
is foundabovethe container.
What unitsis temperature
measured
in the container?
Writean equationrelatingdegreesCelsiusand Kelvin:
|n c reas e t h e t e m pe ra tu re ,w h a th a p p e nstothem otionofthepar tic|es?
We setpressure
to be a constant
value.Whatcausespressure
in the container?
lf the particles
aremovingfasterbutwe don'twantthemto hitthe wallsanymorethanpreviously,
whatis going
to haveto change???Thinkaboutit.
b
Fillin DataTable#2 by selecting
varioustemperatures
and measuring
the corresponding
volumeof the
containerusingthe ruler. use temps between lso K and 4so
Kl
calculatethe valuesas indicated
in the othercolumns.
Trials
Temperature
(T)
Trial1
300 K
Volume(V)
Calculate
k1= (VxT)
Calculate
k, =F
2
3
4
5
6
Whichvariabledid you manipulate(independent)?
Whichvariableis the dependentvariabte?
GraphVolumevs. Temperaturein the followinggraph. Useproperscaling.
Labelthe graphappropriately.
Graphthe line of bestfit.
Lookingat yourdataand graph,describethe relationship
betweentemperature
andvolume.
As the temperature
getscolderand approaches
0 Kelvin,whathappensto the volumeof the gas?
Whichvalueremainsconsistent
in thedatatable?
kr
or
kz
NotCithe othei k-value is worthleis and proves nothing.
Lookingat the topof DataTable#2,whatdoesthis"k"valueequal?
Let'scallthe firstset of datapointsV1andT1andthe secondset of datapointsV2andT2and so on. Sinceall
trialshaveroughlythe samechosenk-value,setthe k-valuesto equaleachother.Writean appropriate
equationusingthevariables
V1,T1,V2,dhdT2.
This is Charles'Law betweenVolumeand Temperatureof a Gas. Learnit. Know it. Useit.
We can usethisformulato predictthevolume(Vr)or temperature
(Tj of anygas. Usethisformulato
completethe following
calculations.
Whendoingthesecalculations,
it is necessary
for the pressure
to have
the sameunits. ldentifyallvariables
andthensubstitute
andsolve.
1. lf a gashasa volumeof 1.25L at a temperature
of 300 K, whatwillthevolumechangeto if the
container
is cooledto 200 K?
2. lf a gashasa volumeof 3.67L at the temperature
of 500 K, whatwillthe volumechangeto if the
container
is heatedto 900 K?
is 22 C hasa volumeof about3.12L. The person
3. A balloonboughtin a storewherethetemperature
is 37" C. Whatis the newvolumeof the
takesthe balloonoutsideon a hotdayof a temperature
balloon?Becarefulof the TempUnits!!!
wouldyou haveto
4. lf you didbuy a 2.75L balloonthat hada temperatureof 23' C, whattemperature
the volumeto 5.00L?
heatthe balloonto in orderto increase