Solved by a verified expert:The Propertiesof Water
Margaret E. Vorndam,
M.S. Version 42-0129-00-01
LAB REPORTASSISTANT
Thisdocumentisnotmeanttobeasubstitute foraformallaboratoryreport.TheLabReport Assistantissimplyasummaryoftheexperiment’squestions,diagramsifneeded,anddatatables
that
shouldbeaddressedinaformallabreport.
Theintentistofacilitatestudents’writing
oflab reports by providing
this informationin an editable
filewhich can be sent to an instructor.
Exercise 1: Surface Tension
RESULTS
A. State
your hypothesis. What do you think will happen?
Table 1: Results of Surface Tension
Trials
Trial #
Paper Clip Weight, grams
Does it Float? Yes/No
1
2
3
4
5Compacted
6 + Detergent
(optional)
B. Record
the results of your trials in the Data
Table 1 above.
C. Did the weight of the paper
clip affectwhether it floatedor not? D.
Did
the size of the paper clip affectwhether
it floatedor not?
E. Did the shape of the paper clip affectwhether it floatedor not?
F. Optional:Did the
additionof detergent
influencethe flotationof
the paper clip? Explain.
QUESTIONS
A. Why must the paper clips, tweezers, and bowl
be clean? B. If one paper clip did not
float,what might be a reason?
C. Was
your original hypothesis supported or refuted?
DISCUSSION
A. Givetwoexampleswherethesurfacetension
ofwaterisimportant.Whyisitimportantin these examples?
B. Wouldotherliquidshavethesamesurfacetensionproperty?
Whyorwhynot?Howmight
you test this (for instance, the behavior of a paper clip and olive
oil)?
C. Is there
a limit to the tensile strength
of the water surface? Explain.
D. What experimental
variables are important to
consider when doing this exercise? E.
What
is the purpose of this exercise?
Exercise
2: Capillary Action
RESULTS
Table 2: Results
of Capillary ActionExercise
Capillary Tube Internal Diameter, mm
Height of Liquid, cm
A. State your
hypothesis. What do you think will
happen? B. Record the results
of your exercise in the Data Table 2.
C. Recordtheaverageresultsofatleastthreeotherstudents’exercisesinatablelikeTable3. Why
is it important to note how
many data sets (N) are
used in the average?
N
(number of data sets averaged) =
Table 3: Results of Capillary
ActionExercise
Capillary Tube
Internal
Diameter, mm
Height of Liquid, cm
D. GraphyourdataresultsfromTables1and2inascattergraph,linegraph,orbargraphsimilar
to
thegraphlayoutinFigure1.Alsopresenttheaverageresultsoftheother
students’datausing a
secondscatter,
lineorbaronthesamegraphsothattheresultsofbothyourdataandother students’datacanbecompared.Thegraphshouldpresenttwoseries
ofdata, yourresultsand the average students’ results,
with Capillary Tube Internal Diameter on the x-axis,
and height of liquidon the y-axis. Note:
Do the graph by hand, or you may use a graphingprogram,
and copy the resultinggraph
to your
work area. Place your graph here:
E. Whatistheadvantageofcomparing
yourdatatothatoftheotherstudents’data?Which
set of data
would you trust the most? Why?
My data from Table 1 is recorded in
(student to specify color of line)
Otherstudents’averagedatafromTable2arerecordedin (studenttospecifycolorof line)
QUESTIONS
A. What
did you observe at
the end timeof the exercise?
B. What
caused the differencein the results
that you obtained?
C. How
did your outcome compare
to that of the other students?
D. Wastherealinear
relationshipbetweenInternal
Diameterandtheheightofthewater?What might
explain this?
E. Was
your original hypothesis supported or refuted?
DISCUSSION
A. Give
two examples
where the capillary actionof water is important. Why is it important?
B. Would
other liquids have the same property? Why or why not? How
might you test this?
C. Bloodinourbodies
travelsthroughcapillariesofdifferinginternaldiameters.Thismeansthat
ourheartcanworklesshard,sincebloodcontainswateraspartofthefluid,
andthecapillary action
of water in tubes helps to move the blood along.
1. Whydoesbloodpressureriseaspatientsexperience
theprogressionofatherosclerotic disease?
Doesthisseemtobecountertowhatyouhavelearnedaboutcapillaryaction?Howdo you
explain the apparent
discrepancy (note: see also c., below)?
2. Inplants,vascular
systemelements called
xylemandphloem
arelineduplikelongstraws fromthe rootofthe
plant tothe leaves.Thexylem
ofplants moves water
anddissolved nutrients up to the leaves. Can you
suggest what
aids the movement of water up the plant, in additionto the capillary action
of water?
3. Why
is it harder to suck a beverage through
a small diameter straw
than through a large
diameter straw?
4. What
experimental variables are important to
consider when doing this exercise? What
couldexplainthedifference
inoutcomesbetweenyourdataandthedataofother students?
5. What
is the purpose of this exercise?
Exercise
3: Density
RESULTS
A. State
your hypothesis. What do you think will happen?
B. Record
what actually happened here:
QUESTIONS
A. What
did you observe in this exercise?
B. How
does this outcome compare to
what you observe
about the actionof ice (the solidform
of water) on liquid water?
C. Was
your original hypothesis supported or refuted?
DISCUSSION
A. Why
is it important that ice floats?
B. Give
two examples
where the property of water
density is important.
C. Do all solids floaton
their liquid forms? Why or why
not?
D. The density of liquid olive oil is about 0.92. What can
you say about the likely
density of solid oil? Why?
E. Will olive oil floator sink if it is added to liquid water? Why?
F. What experimental
variables are important to
consider when doing this exercise?
G.
Attempttofindanother
puresubstance,
likewateroroil,inwhichthesolidformfloatsonthe
liquid form (Note: do not spend more than 5 minutes on
this question!).
H. What did you
learn from this exercise?
Exercise
4: SpecificHeat Capacity
RESULTS
A. State
your hypothesis. What do you think will happen?
B. Whatdifferencedoyouobserveintheheightsofthefrozensolidoilandwaterascompared to
the liquid forms prior to freezing? What
might explain this result?
C. Record
what actually happened in a table similar to Tables 4 and 5
Table 4: Results of
SpecificHeat Exercise for
Water
Ambient
(Room) Temperature
in Which Exercise was Conducted,
ºC.
Time, minutes
Liquid
Collected, mL
All solid ice gone
Table 5: Results of
SpecificHeat Exercise for
Oil
Ambient (Room) Temperature
in Which Exercise was Conducted,
ºC.
Time, minutes
Liquid
Collected, mL
All solid oil gone
D. GraphyourdataresultsfromTable4and5inagraphlikeFigure2.Useascattergraphor
progressivelinegraph,withTimenotedonthex-axis,andmLofliquid
collectedonthey-axis.You
shouldhavetwoscatter plots
orlinesonyourgraph(nottwoseparategraphs)—oneforwater and
oneforoil.Note:youmayuseagraphingprogram,andcopytheresultinggraphtoyourwork
area. Place your graph here:
E. Calculatethemeltingrateforeachofwaterandoil.Themeltingrateisequaltotheslope
ofeachofthe separatelinesofyourgraph,oneforwater, and
oneforoil.Theeasiestwayto
calculatetheslopeforeachistouseyourgraphing
program,andaskittodetermine
thetrendline for you, as follows:
F. Shareyourmeltingrateforwaterandtheoilwithotherstudents,ifpossible.
Makesureto
also obtain the ambient (room) temperature from
the other students. Why?
Table 6: Comparison of MeltingRates
for SpecificHeat
Exercise
Results Reported By
Water, mL/min
Oil, mL/min
General Ambient
Temperature,
ºC.
Student
Student A
Student B
Student C
Student D
Average
=
QUESTIONS
A. Was
your original hypothesis supported or refuted?
B. Whatdoyouobserveconcerning
theplotlineoftheoilversustheplotlineofthewater?
What does this mean?
C. Howcloseisyourmelting
ratetothemeltingratesreportedbyatleastthreeotherstudents for
the water and for the oil?
D. Generally,whatmightyou concludeabouttheamountofspecificheatneeded
tomelt50mL
of water versus 50 mL of oil?
E. Howcould youexplain
thedifferencesin yourdataobservationsastowhenthewaterandoil began
to melt?
F. Whatexperimentalvariables
areimportanttoconsider
whendoingthisexercise?Whatcould explain
the differencein outcomes
between
your data and the data
of other students?
DISCUSSION
A. Howmightyoudesignasimilarexperimenttodeterminewhetherthespecificheat(amount
of heat required to raise
1 gram of a material by 1 ºC) of one substance is more or less than anothersubstance?
Whatvariablesmustyouconsiderinthedesign
ofyourexperiment?Give
anexampleofsuchanexperimentthat comparesthespecificheatsfortwodifferentsubstances.
B. Analternative
energy-savvypersondecidestouse55gallondrumsfilledwithliquidtowarm
her house at night in the winter. She has to make a decisionaboutwhat liquid
willbe the most efficient atstoringheatfromsunlightthatshinesonthedrumsduringtheday.Shouldsheuse water
or oil in the drums? Why?
LABORATORYSUMMARY
What have you
learned from doing this laboratory?
Recent Comments