Water and pH (2)...Title Water and pH (2) Created Date 10/2/2018 9:01:10 PM
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Water, Water Everywhere! Essential Questions: What are the properties of Water? What are Mixtures, Solutions and Suspensions? Why is water important for living things? What is the pH scale?
Transcript of Water and pH (2)...Title Water and pH (2) Created Date 10/2/2018 9:01:10 PM
Water,WaterEverywhere!
EssentialQuestions:WhatarethepropertiesofWater?
WhatareMixtures,SolutionsandSuspensions?Whyiswaterimportantforlivingthings?
WhatisthepHscale?
Yourturn!
IntroductiontoWater
•Waterm
akesup70-95%oforganism
s.
•Consistsof1O
xygenatomand2H
ydrogenatom
sper1waterm
olecule.
•How
iswaterbonded?
•Becauseofitsbondingitcanholdlargemoleculeslikeproteinstogether.
•CarriessubstancesviaO
smosis.
–Servesasm
aterialtransportation–
Blood,plantsap
•Cyclesthroughthekidneysandelim
inatedoutofthebody
FiveMajorPropertiesofW
ater1.
Waterisliquidatroom
temperature
–boilingpointishighat100°C
–low
molecularw
eight–
moleculesareusuallygaseous.
•Waterresiststem
peraturechange.Becausetheboilingpointissohigh,Ittakesalotofenergytoheatw
ater.
•Waterexistsinthreephases:
–Solid(ice)
–Liquid(“w
ater”)–
Gas(vapor)
FiveMajorPropertiesofW
ater
2.Waterhasahighfreezingpoint
–Iceislessdensethanw
ater.
(Thus,icefloatsinw
ater.)
FiveMajorPropertiesofW
ater
3.Wateristheuniversalsolventforpolarandionic
molecules(itcandissolveotherliquids,solids,or
gases)–
Polar:Waterhasaslightlypositive(+)endandaslightly
negative(-)end.–
Hydrophilic:m
eans“water-loving”,m
oleculesthatinteractw
ithwater,solubleinw
ater–
Hydrophobic:m
eans“water-fearing”,insolubleinw
ater
FiveMajorPropertiesofW
ater4.W
ateriswet:
–Hydrogenbondsholdseparatew
atermolecules
together(polarareasattract)
–Slightlynegative(-)O
xygenendisattractedtotheslightlypositive(+)H
ydrogenends.
–Cohesion:attractionofw
atermolecules
toeachother.
–Adhesion:attractionofw
atermolecules
toothertypesofmolecules.
•Exam
ple:Themeniscusinagraduatedcylinder
–Capillaryaction:cohesionandadhesionacttogether,pullingupw
ateragainstgravity.•
Example:Transportationofw
aterfromtherootstotheleaves
ofatree
FiveMajorPropertiesofW
ater
5.Waterhashighsurfacetension
–waterism
oreattractedtoitself(cohesion)thantotheairaroundit
–Stickstogether(+and–attract.)
Yo
u w
ill determ
ine
factors th
at affect S
urface T
ensio
n in
you
r P
enn
y M
ini-lab
tod
ay!
http://www.youtube.com
/watch?v=_Jh1-ElbXlk&
feature=related
Mixtures,Solutions&
SuspensionsAm
ixtureisacombinationofsubstances
wherebothsubstanceskeeptheir
originalproperties.–Physicallym
ixed,notchemically
mixed.
SignsofDehydration
Mixtures,Solutions&
SuspensionsSolution:oneorm
oresubstances(solutes)aredistributedevenlyinanothersubstance(solvent),likew
ater
–Them
oresoluteinasolvent,thehighertheconcentration
–Hom
eostasis:Organism
sregulatetheconcentrationofwaterandotherim
portantsubstancesintheirbodiestomaintainacertainstable
concentrationforlifeprocesses
SignsofDehydration
Mixtures,Solutions&
SuspensionsSuspension–m
ixtureofwaterand
non-dissolvedparticles–Exam
ple:Blood–http://w
ww.youtube.com
/watch?v=PgI80U
e-AMo
SignsofDehydration
pHScale•
pH–ameasureofhow
acidicorbasicsom
ethingis.•
UsepHpaper(litm
uspaper)totest
•Acidsrangefrom
pHof0-6–
AcidsformH+ionsinw
ater–
Example:Lem
on(pH:2)
•Neutralis7–
Example:Purew
aterandblood(pH:7)
•Basesrangefrom
pHof8-14–
BasesformOH-ionsinw
ater–
Example:Am
monia(pH:12)
•Buffers–w
eakacidsandweakbases
thatreactwithstrongacidsorbasesto
preventsuddenchangesinpH.•Usedtom
aintainhomeostasis.
Homeostasis
Theabilityortendencyofanorganismtom
aintaininternalequilibrium
,orbalance,internally.
FightClubScience:NeutralizationReaction
IntheMovie,FightClub,BradPitt’sCharacterputsa
chemicalburn(usingLye,pHof13)onEdw
ardNorton’s
Character'swethand.
–Islyeanacid,abaseoraneutralsubstance?
FightClubScience:NeutralizationReaction
IntheMovie,FightClub,BradPitt’sCharacterputsa
chemicalburn(usingLye,pHof13)onEdw
ardNorton’s
Character'swethand.
–Islyeanacid,abaseoraneutralsubstance?
–Shouldheputw
aterorvinegartostoptheburn?•WhatisthepHofW
ater?•WhatisthepHofVinegar?
FightClubScience:NeutralizationReaction
IntheMovie,FightClub,BradPitt’sCharacterputsa
chemicalburn(usingLye,pHof13)onEdw
ardNorton’s
Character'swethand.
–Islyeanacid,abaseoraneutralsubstance?
–Shouldheputw
aterorvinegartostoptheburn?•WhatisthepHofW
ater?•WhatisthepHofVinegar?
PennyMinilab!
