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Physical and Chemical Change Worksheet
True or False. Iffalse, cotect the underlinedportion of the statementso that it is true.
1. A physical chaneeis a changeof matter from one form to anotherwithout a changein
chemicalproperties.
F 2.4
changeis a changethat occurswhena substance
changescompositionby forming
oneor morenew substances.
T
3. Color changeis evidencethat a chemicalchangemay haveoccurred.
.T
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4.Fizzingor foamingis evidencethat a chegical chaneemay haveoccurred.
F
5. Productionof light is evidencethat
T
hangemay haveoccurred.
6. Productionof heator light is evidencethat a chemicalchangemay haveoccurred.
F
7. A changein odoris evidence
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F
8. Chemicalchangescanbe reversedb
mayhaveoccurred.
Identiff eachof the following as either a Physicalchange(P) or a chemicalchange(C).
1. You cut your hair. P
2. Making a peanut,pretzelandcerealmixture. P
3. Baking sodareactswith vinegarandforms a gas. L
4. A pieceof metalis bentin half.
ls
P
5. An aspirinis crushedinto fine powder.
P
6. Copperturns greenwhen exposedto the environment.
7. Two clearliquids aremixed anda yellow color forms.
8. Bakinscookies. C
g. Diamonds
areusedto scratchgturr. P
'
10.A treeburnsto formashes. C
11.A pieceof paperis crumpled
up. P
12.Waterfreezes
to formice.
13.Foodspoiling.
C
14.A candleburning. L
15.A candlemelting. f
P
c
Analyzing Graphs
The graph at the right plots the amountof light transmitted(% Transm
flask as a functionoftime. Initially, the flask containsonly
air. After a shortperiodof time, a light blue solutionis
o
(,
addedto the reactionflask.After anotherperiodof time, a
tr
o
clear solution is addedto the flask and the entire solution
E
tums dark blue.
o
a reactron
tr
IE
F
1. At what time is the light blue solution addedto the
reactionflask?
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r abov{ t rnrnJes
At what time doesthe dark blue solution begin to form?
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3. The %Transmittance
levelsoffat about8 minutes. What is happeningin the reactionflask?
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4. After 15 minutes,anothersolution is addedto the reactionflask and the o/oTransmittance
returnsto 100%. Did anotherreactiontake place?Pleaseexplain your answer.
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5. Two clear,colorlessliquidsareallowed
to cometo roomtemperature(22 "C).
The timer is startedand then the two
solutionsare mixed togetherto form
anotherclear,colorlessliquid. Looking
at the graphto the right, at what time
were the two solutionsmixed together?
32
30
6
za
o
5 2 6
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* u
/r
obou{ } r",'nule-s
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' x 2
20
0
1
2
3
1
5
6
time(min)
7
8
9
1
0
Date:
A Thought Experiment
A sealedflask of a clear,colorlessliquid is left sittingon an interiorsunnywindowsill. After
aboutan hour,therearedropletsof a clearliquid on the glassabovethe solution,which has
turnedyellow. After two hours,the solutionis dark brownwith clear,colorlessdropletsof liquid
on the glass.After sitting on the windowsill for a week,the walls of the flask havea silvery
lining and both the solution and the dropletsare clear and colorless.
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6. )ftich of the following is not an indicationthat a chemicalreactionhasoccurred?
(g)/formation of liquid dropletsabovethe solution
(b) the solutioncolor changingfrom clearto yellow
(c) the solution color changingfrom brown to clear
(d) formationof a silvery metallicfoil on the walls of the flask
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7. The formationof the silvery lining is an exampleof which of the following indicatorsof
chemicalchange?
JeI evolutionof a gas
(pJdistinct color change
Q)Rrecipitate formation
(d) temperaturechange
8. (Shortanswer)Thereis only onereactiontakingplacein the flask. What is onepossible
reasonfor all ofthe color chanees?
- o n ( p o s r i b \ en e a $ o\ns l f r s Q u q P o c d0 {"i, t { \ i q r ; d
9. (Shortanswer)An observantchemistrystudentis enjoying a glassof iced tea during lunch
(not in the lab!), and shenoticesthat the color of her drink changesasthe ice in the glass
melts. Is a chemicalreactionoccuning?Why or why not?
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